Add golangci (#6418)

59 files changed, 237 insertions, 317 deletions

diff --git a/modules/auth/auth.go b/modules/auth/auth.go
index edb596c240..2a2ee40492 100644
--- a/modules/auth/auth.go
+++ b/modules/auth/auth.go
@@ -214,10 +214,8 @@ func SignedInUser(ctx *macaron.Context, sess session.Store) (*models.User, bool)
 				if err = models.UpdateAccessToken(token); err != nil {
 					log.Error("UpdateAccessToken:  %v", err)
 				}
-			} else {
-				if !models.IsErrAccessTokenNotExist(err) && !models.IsErrAccessTokenEmpty(err) {
-					log.Error("GetAccessTokenBySha: %v", err)
-				}
+			} else if !models.IsErrAccessTokenNotExist(err) && !models.IsErrAccessTokenEmpty(err) {
+				log.Error("GetAccessTokenBySha: %v", err)
 			}
 
 			if u == nil {
@@ -301,12 +299,6 @@ func GetInclude(field reflect.StructField) string {
 	return getRuleBody(field, "Include(")
 }
 
-// FIXME: struct contains a struct
-func validateStruct(obj interface{}) binding.Errors {
-
-	return nil
-}
-
 func validate(errs binding.Errors, data map[string]interface{}, f Form, l macaron.Locale) binding.Errors {
 	if errs.Len() == 0 {
 		return errs
diff --git a/modules/auth/oauth2/oauth2.go b/modules/auth/oauth2/oauth2.go
index 5684f44a89..a2d7116211 100644
--- a/modules/auth/oauth2/oauth2.go
+++ b/modules/auth/oauth2/oauth2.go
@@ -220,8 +220,7 @@ func GetDefaultProfileURL(provider string) string {
 
 // GetDefaultEmailURL return the default email url for the given provider
 func GetDefaultEmailURL(provider string) string {
-	switch provider {
-	case "github":
+	if provider == "github" {
 		return github.EmailURL
 	}
 	return ""
diff --git a/modules/auth/openid/discovery_cache_test.go b/modules/auth/openid/discovery_cache_test.go
index 2e37058cc3..931e5c7945 100644
--- a/modules/auth/openid/discovery_cache_test.go
+++ b/modules/auth/openid/discovery_cache_test.go
@@ -39,7 +39,7 @@ func TestTimedDiscoveryCache(t *testing.T) {
 		t.Errorf("Expected nil, got %v", di)
 	}
 
-	// Sleep one second and try retrive again
+	// Sleep one second and try retrieve again
 	time.Sleep(1 * time.Second)
 
 	if di := dc.Get("foo"); di != nil {
diff --git a/modules/auth/user_form.go b/modules/auth/user_form.go
index 8b9e5877d9..0c8bd30abc 100644
--- a/modules/auth/user_form.go
+++ b/modules/auth/user_form.go
@@ -253,7 +253,7 @@ func (f UpdateThemeForm) IsThemeExists() bool {
 	var exists bool
 
 	for _, v := range setting.UI.Themes {
-		if strings.ToLower(v) == strings.ToLower(f.Theme) {
+		if strings.EqualFold(v, f.Theme) {
 			exists = true
 			break
 		}
diff --git a/modules/base/tool.go b/modules/base/tool.go
index dcf9155a07..4893abff71 100644
--- a/modules/base/tool.go
+++ b/modules/base/tool.go
@@ -44,21 +44,21 @@ var UTF8BOM = []byte{'\xef', '\xbb', '\xbf'}
 // EncodeMD5 encodes string to md5 hex value.
 func EncodeMD5(str string) string {
 	m := md5.New()
-	m.Write([]byte(str))
+	_, _ = m.Write([]byte(str))
 	return hex.EncodeToString(m.Sum(nil))
 }
 
 // EncodeSha1 string to sha1 hex value.
 func EncodeSha1(str string) string {
 	h := sha1.New()
-	h.Write([]byte(str))
+	_, _ = h.Write([]byte(str))
 	return hex.EncodeToString(h.Sum(nil))
 }
 
 // EncodeSha256 string to sha1 hex value.
 func EncodeSha256(str string) string {
 	h := sha256.New()
-	h.Write([]byte(str))
+	_, _ = h.Write([]byte(str))
 	return hex.EncodeToString(h.Sum(nil))
 }
 
@@ -193,7 +193,7 @@ func CreateTimeLimitCode(data string, minutes int, startInf interface{}) string
 
 	// create sha1 encode string
 	sh := sha1.New()
-	sh.Write([]byte(data + setting.SecretKey + startStr + endStr + com.ToStr(minutes)))
+	_, _ = sh.Write([]byte(data + setting.SecretKey + startStr + endStr + com.ToStr(minutes)))
 	encoded := hex.EncodeToString(sh.Sum(nil))
 
 	code := fmt.Sprintf("%s%06d%s", startStr, minutes, encoded)
@@ -425,16 +425,6 @@ const (
 	EByte = PByte * 1024
 )
 
-var bytesSizeTable = map[string]uint64{
-	"b":  Byte,
-	"kb": KByte,
-	"mb": MByte,
-	"gb": GByte,
-	"tb": TByte,
-	"pb": PByte,
-	"eb": EByte,
-}
-
 func logn(n, b float64) float64 {
 	return math.Log(n) / math.Log(b)
 }
@@ -582,27 +572,27 @@ func IsTextFile(data []byte) bool {
 	if len(data) == 0 {
 		return true
 	}
-	return strings.Index(http.DetectContentType(data), "text/") != -1
+	return strings.Contains(http.DetectContentType(data), "text/")
 }
 
 // IsImageFile detects if data is an image format
 func IsImageFile(data []byte) bool {
-	return strings.Index(http.DetectContentType(data), "image/") != -1
+	return strings.Contains(http.DetectContentType(data), "image/")
 }
 
 // IsPDFFile detects if data is a pdf format
 func IsPDFFile(data []byte) bool {
-	return strings.Index(http.DetectContentType(data), "application/pdf") != -1
+	return strings.Contains(http.DetectContentType(data), "application/pdf")
 }
 
 // IsVideoFile detects if data is an video format
 func IsVideoFile(data []byte) bool {
-	return strings.Index(http.DetectContentType(data), "video/") != -1
+	return strings.Contains(http.DetectContentType(data), "video/")
 }
 
 // IsAudioFile detects if data is an video format
 func IsAudioFile(data []byte) bool {
-	return strings.Index(http.DetectContentType(data), "audio/") != -1
+	return strings.Contains(http.DetectContentType(data), "audio/")
 }
 
 // EntryIcon returns the octicon class for displaying files/directories
diff --git a/modules/base/tool_test.go b/modules/base/tool_test.go
index ec9bc1eb52..fa61e5dfb1 100644
--- a/modules/base/tool_test.go
+++ b/modules/base/tool_test.go
@@ -287,20 +287,19 @@ func TestHtmlTimeSince(t *testing.T) {
 }
 
 func TestFileSize(t *testing.T) {
-	var size int64
-	size = 512
+	var size int64 = 512
 	assert.Equal(t, "512B", FileSize(size))
-	size = size * 1024
+	size *= 1024
 	assert.Equal(t, "512KB", FileSize(size))
-	size = size * 1024
+	size *= 1024
 	assert.Equal(t, "512MB", FileSize(size))
-	size = size * 1024
+	size *= 1024
 	assert.Equal(t, "512GB", FileSize(size))
-	size = size * 1024
+	size *= 1024
 	assert.Equal(t, "512TB", FileSize(size))
-	size = size * 1024
+	size *= 1024
 	assert.Equal(t, "512PB", FileSize(size))
-	size = size * 4
+	size *= 4
 	assert.Equal(t, "2.0EB", FileSize(size))
 }
 
diff --git a/modules/cache/cache.go b/modules/cache/cache.go
index a2d6c724c8..a7412f109f 100644
--- a/modules/cache/cache.go
+++ b/modules/cache/cache.go
@@ -43,7 +43,10 @@ func GetInt(key string, getFunc func() (int, error)) (int, error) {
 		if value, err = getFunc(); err != nil {
 			return value, err
 		}
-		conn.Put(key, value, int64(setting.CacheService.TTL.Seconds()))
+		err = conn.Put(key, value, int64(setting.CacheService.TTL.Seconds()))
+		if err != nil {
+			return 0, err
+		}
 	}
 	switch value := conn.Get(key).(type) {
 	case int:
@@ -72,7 +75,10 @@ func GetInt64(key string, getFunc func() (int64, error)) (int64, error) {
 		if value, err = getFunc(); err != nil {
 			return value, err
 		}
-		conn.Put(key, value, int64(setting.CacheService.TTL.Seconds()))
+		err = conn.Put(key, value, int64(setting.CacheService.TTL.Seconds()))
+		if err != nil {
+			return 0, err
+		}
 	}
 	switch value := conn.Get(key).(type) {
 	case int64:
@@ -93,5 +99,5 @@ func Remove(key string) {
 	if conn == nil {
 		return
 	}
-	conn.Delete(key)
+	_ = conn.Delete(key)
 }
diff --git a/modules/context/context.go b/modules/context/context.go
index 1699d7aecc..b7c77ac460 100644
--- a/modules/context/context.go
+++ b/modules/context/context.go
@@ -130,7 +130,6 @@ func (ctx *Context) RedirectToFirst(location ...string) {
 	}
 
 	ctx.Redirect(setting.AppSubURL + "/")
-	return
 }
 
 // HTML calls Context.HTML and converts template name to string.
@@ -266,7 +265,7 @@ func Contexter() macaron.Handler {
 			}
 			c.Header().Set("Content-Type", "text/html")
 			c.WriteHeader(http.StatusOK)
-			c.Write([]byte(com.Expand(`<!doctype html>
+			_, _ = c.Write([]byte(com.Expand(`<!doctype html>
 <html>
 	<head>
 		<meta name="go-import" content="{GoGetImport} git {CloneLink}">
diff --git a/modules/context/pagination.go b/modules/context/pagination.go
index 4795f650fb..390b4dbdd7 100644
--- a/modules/context/pagination.go
+++ b/modules/context/pagination.go
@@ -39,7 +39,7 @@ func (p *Pagination) AddParam(ctx *Context, paramKey string, ctxKey string) {
 
 // GetParams returns the configured URL params
 func (p *Pagination) GetParams() template.URL {
-	return template.URL(strings.Join(p.urlParams[:], "&"))
+	return template.URL(strings.Join(p.urlParams, "&"))
 }
 
 // SetDefaultParams sets common pagination params that are often used
diff --git a/modules/context/repo.go b/modules/context/repo.go
index 0908340879..096f3c0a5d 100644
--- a/modules/context/repo.go
+++ b/modules/context/repo.go
@@ -455,15 +455,13 @@ func RepoAssignment() macaron.Handler {
 				ctx.Repo.PullRequest.BaseRepo = repo.BaseRepo
 				ctx.Repo.PullRequest.Allowed = true
 				ctx.Repo.PullRequest.HeadInfo = ctx.Repo.Owner.Name + ":" + ctx.Repo.BranchName
-			} else {
+			} else if repo.AllowsPulls() {
 				// Or, this is repository accepts pull requests between branches.
-				if repo.AllowsPulls() {
-					ctx.Data["BaseRepo"] = repo
-					ctx.Repo.PullRequest.BaseRepo = repo
-					ctx.Repo.PullRequest.Allowed = true
-					ctx.Repo.PullRequest.SameRepo = true
-					ctx.Repo.PullRequest.HeadInfo = ctx.Repo.BranchName
-				}
+				ctx.Data["BaseRepo"] = repo
+				ctx.Repo.PullRequest.BaseRepo = repo
+				ctx.Repo.PullRequest.Allowed = true
+				ctx.Repo.PullRequest.SameRepo = true
+				ctx.Repo.PullRequest.HeadInfo = ctx.Repo.BranchName
 			}
 		}
 		ctx.Data["PullRequestCtx"] = ctx.Repo.PullRequest
diff --git a/modules/git/blob.go b/modules/git/blob.go
index 171b4a1010..73ac89dfdf 100644
--- a/modules/git/blob.go
+++ b/modules/git/blob.go
@@ -50,12 +50,12 @@ func (b *Blob) GetBlobContentBase64() (string, error) {
 
 	go func() {
 		_, err := io.Copy(encoder, dataRc)
-		encoder.Close()
+		_ = encoder.Close()
 
 		if err != nil {
-			pw.CloseWithError(err)
+			_ = pw.CloseWithError(err)
 		} else {
-			pw.Close()
+			_ = pw.Close()
 		}
 	}()
 
diff --git a/modules/git/commit.go b/modules/git/commit.go
index 7b64a300ab..c86ece9848 100644
--- a/modules/git/commit.go
+++ b/modules/git/commit.go
@@ -133,7 +133,7 @@ func (c *Commit) ParentCount() int {
 
 func isImageFile(data []byte) (string, bool) {
 	contentType := http.DetectContentType(data)
-	if strings.Index(contentType, "image/") != -1 {
+	if strings.Contains(contentType, "image/") {
 		return contentType, true
 	}
 	return contentType, false
@@ -206,8 +206,7 @@ func CommitChanges(repoPath string, opts CommitChangesOptions) error {
 }
 
 func commitsCount(repoPath, revision, relpath string) (int64, error) {
-	var cmd *Command
-	cmd = NewCommand("rev-list", "--count")
+	cmd := NewCommand("rev-list", "--count")
 	cmd.AddArguments(revision)
 	if len(relpath) > 0 {
 		cmd.AddArguments("--", relpath)
@@ -263,7 +262,7 @@ type SearchCommitsOptions struct {
 	All                 bool
 }
 
-// NewSearchCommitsOptions contruct a SearchCommitsOption from a space-delimited search string
+// NewSearchCommitsOptions construct a SearchCommitsOption from a space-delimited search string
 func NewSearchCommitsOptions(searchString string, forAllRefs bool) SearchCommitsOptions {
 	var keywords, authors, committers []string
 	var after, before string
diff --git a/modules/git/commit_info.go b/modules/git/commit_info.go
index da430a21cd..43723d169b 100644
--- a/modules/git/commit_info.go
+++ b/modules/git/commit_info.go
@@ -87,16 +87,6 @@ func getCommitTree(c *object.Commit, treePath string) (*object.Tree, error) {
 	return tree, nil
 }
 
-func getFullPath(treePath, path string) string {
-	if treePath != "" {
-		if path != "" {
-			return treePath + "/" + path
-		}
-		return treePath
-	}
-	return path
-}
-
 func getFileHashes(c *object.Commit, treePath string, paths []string) (map[string]plumbing.Hash, error) {
 	tree, err := getCommitTree(c, treePath)
 	if err == object.ErrDirectoryNotFound {
diff --git a/modules/git/repo.go b/modules/git/repo.go
index 4be3164130..f5d7ee63bb 100644
--- a/modules/git/repo.go
+++ b/modules/git/repo.go
@@ -58,21 +58,21 @@ func (repo *Repository) parsePrettyFormatLogToList(logs []byte) (*list.List, err
 // IsRepoURLAccessible checks if given repository URL is accessible.
 func IsRepoURLAccessible(url string) bool {
 	_, err := NewCommand("ls-remote", "-q", "-h", url, "HEAD").Run()
-	if err != nil {
-		return false
-	}
-	return true
+	return err == nil
 }
 
 // InitRepository initializes a new Git repository.
 func InitRepository(repoPath string, bare bool) error {
-	os.MkdirAll(repoPath, os.ModePerm)
+	err := os.MkdirAll(repoPath, os.ModePerm)
+	if err != nil {
+		return err
+	}
 
 	cmd := NewCommand("init")
 	if bare {
 		cmd.AddArguments("--bare")
 	}
-	_, err := cmd.RunInDir(repoPath)
+	_, err = cmd.RunInDir(repoPath)
 	return err
 }
 
diff --git a/modules/git/repo_branch.go b/modules/git/repo_branch.go
index 116bdbee82..05eba1e30e 100644
--- a/modules/git/repo_branch.go
+++ b/modules/git/repo_branch.go
@@ -29,10 +29,7 @@ func IsBranchExist(repoPath, name string) bool {
 // IsBranchExist returns true if given branch exists in current repository.
 func (repo *Repository) IsBranchExist(name string) bool {
 	_, err := repo.gogitRepo.Reference(plumbing.ReferenceName(BranchPrefix+name), true)
-	if err != nil {
-		return false
-	}
-	return true
+	return err == nil
 }
 
 // Branch represents a Git branch.
@@ -77,7 +74,7 @@ func (repo *Repository) GetBranches() ([]string, error) {
 		return nil, err
 	}
 
-	branches.ForEach(func(branch *plumbing.Reference) error {
+	_ = branches.ForEach(func(branch *plumbing.Reference) error {
 		branchNames = append(branchNames, strings.TrimPrefix(branch.Name().String(), BranchPrefix))
 		return nil
 	})
diff --git a/modules/git/repo_commit.go b/modules/git/repo_commit.go
index 501ea88e40..8ea2a33145 100644
--- a/modules/git/repo_commit.go
+++ b/modules/git/repo_commit.go
@@ -31,10 +31,7 @@ func (repo *Repository) GetRefCommitID(name string) (string, error) {
 func (repo *Repository) IsCommitExist(name string) bool {
 	hash := plumbing.NewHash(name)
 	_, err := repo.gogitRepo.CommitObject(hash)
-	if err != nil {
-		return false
-	}
-	return true
+	return err == nil
 }
 
 // GetBranchCommitID returns last commit ID string of given branch.
diff --git a/modules/git/repo_compare.go b/modules/git/repo_compare.go
index 42f0b9ad0c..ddc8109720 100644
--- a/modules/git/repo_compare.go
+++ b/modules/git/repo_compare.go
@@ -13,6 +13,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	logger "code.gitea.io/gitea/modules/log"
 )
 
 // CompareInfo represents needed information for comparing references.
@@ -55,7 +57,11 @@ func (repo *Repository) GetCompareInfo(basePath, baseBranch, headBranch string)
 		if err = repo.AddRemote(tmpRemote, basePath, true); err != nil {
 			return nil, fmt.Errorf("AddRemote: %v", err)
 		}
-		defer repo.RemoveRemote(tmpRemote)
+		defer func() {
+			if err := repo.RemoveRemote(tmpRemote); err != nil {
+				logger.Error("GetPullRequestInfo: RemoveRemote: %v", err)
+			}
+		}()
 	}
 
 	compareInfo := new(CompareInfo)
diff --git a/modules/git/repo_tag.go b/modules/git/repo_tag.go
index 08d66262c1..df49e9acd6 100644
--- a/modules/git/repo_tag.go
+++ b/modules/git/repo_tag.go
@@ -24,10 +24,7 @@ func IsTagExist(repoPath, name string) bool {
 // IsTagExist returns true if given tag exists in the repository.
 func (repo *Repository) IsTagExist(name string) bool {
 	_, err := repo.gogitRepo.Reference(plumbing.ReferenceName(TagPrefix+name), true)
-	if err != nil {
-		return false
-	}
-	return true
+	return err == nil
 }
 
 // CreateTag create one tag in the repository
@@ -221,7 +218,7 @@ func (repo *Repository) GetTags() ([]string, error) {
 		return nil, err
 	}
 
-	tags.ForEach(func(tag *plumbing.Reference) error {
+	_ = tags.ForEach(func(tag *plumbing.Reference) error {
 		tagNames = append(tagNames, strings.TrimPrefix(tag.Name().String(), TagPrefix))
 		return nil
 	})
diff --git a/modules/git/utils.go b/modules/git/utils.go
index 8f010321cf..83cd21f34e 100644
--- a/modules/git/utils.go
+++ b/modules/git/utils.go
@@ -7,7 +7,6 @@ package git
 import (
 	"fmt"
 	"os"
-	"path/filepath"
 	"strings"
 	"sync"
 )
@@ -75,13 +74,6 @@ func concatenateError(err error, stderr string) error {
 	return fmt.Errorf("%v - %s", err, stderr)
 }
 
-// If the object is stored in its own file (i.e not in a pack file),
-// this function returns the full path to the object file.
-// It does not test if the file exists.
-func filepathFromSHA1(rootdir, sha1 string) string {
-	return filepath.Join(rootdir, "objects", sha1[:2], sha1[2:])
-}
-
 // RefEndName return the end name of a ref name
 func RefEndName(refStr string) string {
 	if strings.HasPrefix(refStr, BranchPrefix) {
diff --git a/modules/gzip/gzip.go b/modules/gzip/gzip.go
index 4a4a797c7a..0d10071830 100644
--- a/modules/gzip/gzip.go
+++ b/modules/gzip/gzip.go
@@ -74,7 +74,6 @@ func (wp *WriterPool) Put(w *gzip.Writer) {
 }
 
 var writerPool WriterPool
-var regex regexp.Regexp
 
 // Options represents the configuration for the gzip middleware
 type Options struct {
@@ -116,7 +115,7 @@ func Middleware(options ...Options) macaron.Handler {
 		if rangeHdr := ctx.Req.Header.Get(rangeHeader); rangeHdr != "" {
 
 			match := regex.FindStringSubmatch(rangeHdr)
-			if match != nil && len(match) > 1 {
+			if len(match) > 1 {
 				return
 			}
 		}
@@ -270,9 +269,8 @@ func (proxy *ProxyResponseWriter) Close() error {
 
 	if proxy.writer == nil {
 		err := proxy.startPlain()
-
 		if err != nil {
-			err = fmt.Errorf("GzipMiddleware: write to regular responseWriter at close gets error: %q", err.Error())
+			return fmt.Errorf("GzipMiddleware: write to regular responseWriter at close gets error: %q", err.Error())
 		}
 	}
 
diff --git a/modules/httplib/httplib.go b/modules/httplib/httplib.go
index c96e04c35f..90bbe8f12a 100644
--- a/modules/httplib/httplib.go
+++ b/modules/httplib/httplib.go
@@ -263,7 +263,7 @@ func (r *Request) getResponse() (*http.Response, error) {
 	}
 
 	if r.req.Method == "GET" && len(paramBody) > 0 {
-		if strings.Index(r.url, "?") != -1 {
+		if strings.Contains(r.url, "?") {
 			r.url += "&" + paramBody
 		} else {
 			r.url = r.url + "?" + paramBody
@@ -290,10 +290,13 @@ func (r *Request) getResponse() (*http.Response, error) {
 					}
 				}
 				for k, v := range r.params {
-					bodyWriter.WriteField(k, v)
+					err := bodyWriter.WriteField(k, v)
+					if err != nil {
+						log.Fatal(err)
+					}
 				}
-				bodyWriter.Close()
-				pw.Close()
+				_ = bodyWriter.Close()
+				_ = pw.Close()
 			}()
 			r.Header("Content-Type", bodyWriter.FormDataContentType())
 			r.req.Body = ioutil.NopCloser(pr)
@@ -323,18 +326,15 @@ func (r *Request) getResponse() (*http.Response, error) {
 			Proxy:           proxy,
 			Dial:            TimeoutDialer(r.setting.ConnectTimeout, r.setting.ReadWriteTimeout),
 		}
-	} else {
-		// if r.transport is *http.Transport then set the settings.
-		if t, ok := trans.(*http.Transport); ok {
-			if t.TLSClientConfig == nil {
-				t.TLSClientConfig = r.setting.TLSClientConfig
-			}
-			if t.Proxy == nil {
-				t.Proxy = r.setting.Proxy
-			}
-			if t.Dial == nil {
-				t.Dial = TimeoutDialer(r.setting.ConnectTimeout, r.setting.ReadWriteTimeout)
-			}
+	} else if t, ok := trans.(*http.Transport); ok {
+		if t.TLSClientConfig == nil {
+			t.TLSClientConfig = r.setting.TLSClientConfig
+		}
+		if t.Proxy == nil {
+			t.Proxy = r.setting.Proxy
+		}
+		if t.Dial == nil {
+			t.Dial = TimeoutDialer(r.setting.ConnectTimeout, r.setting.ReadWriteTimeout)
 		}
 	}
 
@@ -461,7 +461,6 @@ func TimeoutDialer(cTimeout time.Duration, rwTimeout time.Duration) func(net, ad
 		if err != nil {
 			return nil, err
 		}
-		conn.SetDeadline(time.Now().Add(rwTimeout))
-		return conn, nil
+		return conn, conn.SetDeadline(time.Now().Add(rwTimeout))
 	}
 }
diff --git a/modules/indexer/indexer.go b/modules/indexer/indexer.go
index 9e12a7f501..29261c693b 100644
--- a/modules/indexer/indexer.go
+++ b/modules/indexer/indexer.go
@@ -5,7 +5,6 @@
 package indexer
 
 import (
-	"fmt"
 	"os"
 	"strconv"
 
@@ -24,15 +23,6 @@ func indexerID(id int64) string {
 	return strconv.FormatInt(id, 36)
 }
 
-// idOfIndexerID the integer id associated with an indexer id
-func idOfIndexerID(indexerID string) (int64, error) {
-	id, err := strconv.ParseInt(indexerID, 36, 64)
-	if err != nil {
-		return 0, fmt.Errorf("Unexpected indexer ID %s: %v", indexerID, err)
-	}
-	return id, nil
-}
-
 // numericEqualityQuery a numeric equality query for the given value and field
 func numericEqualityQuery(value int64, field string) *query.NumericRangeQuery {
 	f := float64(value)
@@ -42,13 +32,6 @@ func numericEqualityQuery(value int64, field string) *query.NumericRangeQuery {
 	return q
 }
 
-func newMatchPhraseQuery(matchPhrase, field, analyzer string) *query.MatchPhraseQuery {
-	q := bleve.NewMatchPhraseQuery(matchPhrase)
-	q.FieldVal = field
-	q.Analyzer = analyzer
-	return q
-}
-
 const unicodeNormalizeName = "unicodeNormalize"
 
 func addUnicodeNormalizeTokenFilter(m *mapping.IndexMappingImpl) error {
diff --git a/modules/indexer/issues/indexer.go b/modules/indexer/issues/indexer.go
index 75e6893b87..df8bfd6305 100644
--- a/modules/indexer/issues/indexer.go
+++ b/modules/indexer/issues/indexer.go
@@ -101,7 +101,12 @@ func InitIssueIndexer(syncReindex bool) error {
 		return fmt.Errorf("Unsupported indexer queue type: %v", setting.Indexer.IssueQueueType)
 	}
 
-	go issueIndexerQueue.Run()
+	go func() {
+		err = issueIndexerQueue.Run()
+		if err != nil {
+			log.Error("issueIndexerQueue.Run: %v", err)
+		}
+	}()
 
 	if populate {
 		if syncReindex {
@@ -161,7 +166,7 @@ func UpdateIssueIndexer(issue *models.Issue) {
 			comments = append(comments, comment.Content)
 		}
 	}
-	issueIndexerQueue.Push(&IndexerData{
+	_ = issueIndexerQueue.Push(&IndexerData{
 		ID:       issue.ID,
 		RepoID:   issue.RepoID,
 		Title:    issue.Title,
@@ -179,11 +184,11 @@ func DeleteRepoIssueIndexer(repo *models.Repository) {
 		return
 	}
 
-	if len(ids) <= 0 {
+	if len(ids) == 0 {
 		return
 	}
 
-	issueIndexerQueue.Push(&IndexerData{
+	_ = issueIndexerQueue.Push(&IndexerData{
 		IDs:      ids,
 		IsDelete: true,
 	})
diff --git a/modules/indexer/issues/queue_channel.go b/modules/indexer/issues/queue_channel.go
index bd92f6b7b1..b6458d3eb5 100644
--- a/modules/indexer/issues/queue_channel.go
+++ b/modules/indexer/issues/queue_channel.go
@@ -34,20 +34,20 @@ func (c *ChannelQueue) Run() error {
 		select {
 		case data := <-c.queue:
 			if data.IsDelete {
-				c.indexer.Delete(data.IDs...)
+				_ = c.indexer.Delete(data.IDs...)
 				continue
 			}
 
 			datas = append(datas, data)
 			if len(datas) >= c.batchNumber {
-				c.indexer.Index(datas)
+				_ = c.indexer.Index(datas)
 				// TODO: save the point
 				datas = make([]*IndexerData, 0, c.batchNumber)
 			}
 		case <-time.After(time.Millisecond * 100):
 			i++
 			if i >= 3 && len(datas) > 0 {
-				c.indexer.Index(datas)
+				_ = c.indexer.Index(datas)
 				// TODO: save the point
 				datas = make([]*IndexerData, 0, c.batchNumber)
 			}
diff --git a/modules/indexer/issues/queue_disk.go b/modules/indexer/issues/queue_disk.go
index cf9e6aee22..e5ac2a7981 100644
--- a/modules/indexer/issues/queue_disk.go
+++ b/modules/indexer/issues/queue_disk.go
@@ -44,7 +44,7 @@ func (l *LevelQueue) Run() error {
 	for {
 		i++
 		if len(datas) > l.batchNumber || (len(datas) > 0 && i > 3) {
-			l.indexer.Index(datas)
+			_ = l.indexer.Index(datas)
 			datas = make([]*IndexerData, 0, l.batchNumber)
 			i = 0
 			continue
@@ -59,7 +59,7 @@ func (l *LevelQueue) Run() error {
 			continue
 		}
 
-		if len(bs) <= 0 {
+		if len(bs) == 0 {
 			time.Sleep(time.Millisecond * 100)
 			continue
 		}
diff --git a/modules/indexer/issues/queue_redis.go b/modules/indexer/issues/queue_redis.go
index a9434c4f92..aeccd7920c 100644
--- a/modules/indexer/issues/queue_redis.go
+++ b/modules/indexer/issues/queue_redis.go
@@ -96,12 +96,12 @@ func (r *RedisQueue) Run() error {
 
 		i++
 		if len(datas) > r.batchNumber || (len(datas) > 0 && i > 3) {
-			r.indexer.Index(datas)
+			_ = r.indexer.Index(datas)
 			datas = make([]*IndexerData, 0, r.batchNumber)
 			i = 0
 		}
 
-		if len(bs) <= 0 {
+		if len(bs) == 0 {
 			time.Sleep(time.Millisecond * 100)
 			continue
 		}
diff --git a/modules/lfs/locks.go b/modules/lfs/locks.go
index b1ca2f094a..4516ba01ae 100644
--- a/modules/lfs/locks.go
+++ b/modules/lfs/locks.go
@@ -17,7 +17,7 @@ import (
 )
 
 //checkIsValidRequest check if it a valid request in case of bad request it write the response to ctx.
-func checkIsValidRequest(ctx *context.Context, post bool) bool {
+func checkIsValidRequest(ctx *context.Context) bool {
 	if !setting.LFS.StartServer {
 		writeStatus(ctx, 404)
 		return false
@@ -35,13 +35,6 @@ func checkIsValidRequest(ctx *context.Context, post bool) bool {
 		}
 		ctx.User = user
 	}
-	if post {
-		mediaParts := strings.Split(ctx.Req.Header.Get("Content-Type"), ";")
-		if mediaParts[0] != metaMediaType {
-			writeStatus(ctx, 400)
-			return false
-		}
-	}
 	return true
 }
 
@@ -71,7 +64,7 @@ func handleLockListOut(ctx *context.Context, repo *models.Repository, lock *mode
 
 // GetListLockHandler list locks
 func GetListLockHandler(ctx *context.Context) {
-	if !checkIsValidRequest(ctx, false) {
+	if !checkIsValidRequest(ctx) {
 		return
 	}
 	ctx.Resp.Header().Set("Content-Type", metaMediaType)
@@ -135,7 +128,7 @@ func GetListLockHandler(ctx *context.Context) {
 
 // PostLockHandler create lock
 func PostLockHandler(ctx *context.Context) {
-	if !checkIsValidRequest(ctx, false) {
+	if !checkIsValidRequest(ctx) {
 		return
 	}
 	ctx.Resp.Header().Set("Content-Type", metaMediaType)
@@ -198,7 +191,7 @@ func PostLockHandler(ctx *context.Context) {
 
 // VerifyLockHandler list locks for verification
 func VerifyLockHandler(ctx *context.Context) {
-	if !checkIsValidRequest(ctx, false) {
+	if !checkIsValidRequest(ctx) {
 		return
 	}
 	ctx.Resp.Header().Set("Content-Type", metaMediaType)
@@ -249,7 +242,7 @@ func VerifyLockHandler(ctx *context.Context) {
 
 // UnLockHandler delete locks
 func UnLockHandler(ctx *context.Context) {
-	if !checkIsValidRequest(ctx, false) {
+	if !checkIsValidRequest(ctx) {
 		return
 	}
 	ctx.Resp.Header().Set("Content-Type", metaMediaType)
diff --git a/modules/lfs/server.go b/modules/lfs/server.go
index 7e20aa8515..bf5355acfc 100644
--- a/modules/lfs/server.go
+++ b/modules/lfs/server.go
@@ -152,7 +152,7 @@ func getContentHandler(ctx *context.Context) {
 	if rangeHdr := ctx.Req.Header.Get("Range"); rangeHdr != "" {
 		regex := regexp.MustCompile(`bytes=(\d+)\-.*`)
 		match := regex.FindStringSubmatch(rangeHdr)
-		if match != nil && len(match) > 1 {
+		if len(match) > 1 {
 			statusCode = 206
 			fromByte, _ = strconv.ParseInt(match[1], 10, 32)
 			ctx.Resp.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", fromByte, meta.Size-1, meta.Size-fromByte))
@@ -178,8 +178,8 @@ func getContentHandler(ctx *context.Context) {
 	}
 
 	ctx.Resp.WriteHeader(statusCode)
-	io.Copy(ctx.Resp, content)
-	content.Close()
+	_, _ = io.Copy(ctx.Resp, content)
+	_ = content.Close()
 	logRequest(ctx.Req, statusCode)
 }
 
@@ -196,7 +196,7 @@ func getMetaHandler(ctx *context.Context) {
 
 	if ctx.Req.Method == "GET" {
 		enc := json.NewEncoder(ctx.Resp)
-		enc.Encode(Represent(rv, meta, true, false))
+		_ = enc.Encode(Represent(rv, meta, true, false))
 	}
 
 	logRequest(ctx.Req, 200)
@@ -249,7 +249,7 @@ func PostHandler(ctx *context.Context) {
 	ctx.Resp.WriteHeader(sentStatus)
 
 	enc := json.NewEncoder(ctx.Resp)
-	enc.Encode(Represent(rv, meta, meta.Existing, true))
+	_ = enc.Encode(Represent(rv, meta, meta.Existing, true))
 	logRequest(ctx.Req, sentStatus)
 }
 
@@ -313,7 +313,7 @@ func BatchHandler(ctx *context.Context) {
 	respobj := &BatchResponse{Objects: responseObjects}
 
 	enc := json.NewEncoder(ctx.Resp)
-	enc.Encode(respobj)
+	_ = enc.Encode(respobj)
 	logRequest(ctx.Req, 200)
 }
 
diff --git a/modules/log/colors.go b/modules/log/colors.go
index 0ec8ce4ba8..c29741634f 100644
--- a/modules/log/colors.go
+++ b/modules/log/colors.go
@@ -208,7 +208,7 @@ normalLoop:
 
 		if i > lasti {
 			written, err := c.w.Write(bytes[lasti:i])
-			totalWritten = totalWritten + written
+			totalWritten += written
 			if err != nil {
 				return totalWritten, err
 			}
@@ -243,7 +243,7 @@ normalLoop:
 					if bytes[j] == 'm' {
 						if c.mode == allowColor {
 							written, err := c.w.Write(bytes[i : j+1])
-							totalWritten = totalWritten + written
+							totalWritten += written
 							if err != nil {
 								return totalWritten, err
 							}
@@ -278,7 +278,7 @@ func ColorSprintf(format string, args ...interface{}) string {
 		}
 		return fmt.Sprintf(format, v...)
 	}
-	return fmt.Sprintf(format)
+	return format
 }
 
 // ColorFprintf will write to the provided writer similar to ColorSprintf
@@ -290,7 +290,7 @@ func ColorFprintf(w io.Writer, format string, args ...interface{}) (int, error)
 		}
 		return fmt.Fprintf(w, format, v...)
 	}
-	return fmt.Fprintf(w, format)
+	return fmt.Fprint(w, format)
 }
 
 // ColorFormatted structs provide their own colored string when formatted with ColorSprintf
diff --git a/modules/log/conn.go b/modules/log/conn.go
index bd76855168..8816664526 100644
--- a/modules/log/conn.go
+++ b/modules/log/conn.go
@@ -67,7 +67,10 @@ func (i *connWriter) connect() error {
 	}
 
 	if tcpConn, ok := conn.(*net.TCPConn); ok {
-		tcpConn.SetKeepAlive(true)
+		err = tcpConn.SetKeepAlive(true)
+		if err != nil {
+			return err
+		}
 	}
 
 	i.innerWriter = conn
diff --git a/modules/log/conn_test.go b/modules/log/conn_test.go
index 380a115d96..cc3d758fa9 100644
--- a/modules/log/conn_test.go
+++ b/modules/log/conn_test.go
@@ -24,7 +24,6 @@ func listenReadAndClose(t *testing.T, l net.Listener, expected string) {
 
 	assert.NoError(t, err)
 	assert.Equal(t, expected, string(written))
-	return
 }
 
 func TestConnLogger(t *testing.T) {
diff --git a/modules/log/event.go b/modules/log/event.go
index 2ec1f9587d..37efa3c230 100644
--- a/modules/log/event.go
+++ b/modules/log/event.go
@@ -79,7 +79,7 @@ func (l *ChannelledLog) Start() {
 				return
 			}
 			l.loggerProvider.Flush()
-		case _, _ = <-l.close:
+		case <-l.close:
 			l.closeLogger()
 			return
 		}
@@ -104,7 +104,6 @@ func (l *ChannelledLog) closeLogger() {
 	l.loggerProvider.Flush()
 	l.loggerProvider.Close()
 	l.closed <- true
-	return
 }
 
 // Close this ChannelledLog
@@ -228,7 +227,6 @@ func (m *MultiChannelledLog) closeLoggers() {
 	}
 	m.mutex.Unlock()
 	m.closed <- true
-	return
 }
 
 // Start processing the MultiChannelledLog
diff --git a/modules/log/file.go b/modules/log/file.go
index cdda85d626..877820b8be 100644
--- a/modules/log/file.go
+++ b/modules/log/file.go
@@ -223,7 +223,7 @@ func compressOldLogFile(fname string, compressionLevel int) error {
 
 func (log *FileLogger) deleteOldLog() {
 	dir := filepath.Dir(log.Filename)
-	filepath.Walk(dir, func(path string, info os.FileInfo, err error) (returnErr error) {
+	_ = filepath.Walk(dir, func(path string, info os.FileInfo, err error) (returnErr error) {
 		defer func() {
 			if r := recover(); r != nil {
 				returnErr = fmt.Errorf("Unable to delete old log '%s', error: %+v", path, r)
@@ -246,7 +246,7 @@ func (log *FileLogger) deleteOldLog() {
 // there are no buffering messages in file logger in memory.
 // flush file means sync file from disk.
 func (log *FileLogger) Flush() {
-	log.mw.fd.Sync()
+	_ = log.mw.fd.Sync()
 }
 
 // GetName returns the default name for this implementation
diff --git a/modules/log/file_test.go b/modules/log/file_test.go
index 648db6f393..38279315ab 100644
--- a/modules/log/file_test.go
+++ b/modules/log/file_test.go
@@ -103,7 +103,7 @@ func TestFileLogger(t *testing.T) {
 	assert.Equal(t, expected, string(logData))
 
 	event.level = WARN
-	expected = expected + fmt.Sprintf("%s%s %s:%d:%s [%c] %s\n", prefix, dateString, event.filename, event.line, event.caller, strings.ToUpper(event.level.String())[0], event.msg)
+	expected += fmt.Sprintf("%s%s %s:%d:%s [%c] %s\n", prefix, dateString, event.filename, event.line, event.caller, strings.ToUpper(event.level.String())[0], event.msg)
 	fileLogger.LogEvent(&event)
 	fileLogger.Flush()
 	logData, err = ioutil.ReadFile(filename)
@@ -130,7 +130,7 @@ func TestFileLogger(t *testing.T) {
 	err = realFileLogger.DoRotate()
 	assert.Error(t, err)
 
-	expected = expected + fmt.Sprintf("%s%s %s:%d:%s [%c] %s\n", prefix, dateString, event.filename, event.line, event.caller, strings.ToUpper(event.level.String())[0], event.msg)
+	expected += fmt.Sprintf("%s%s %s:%d:%s [%c] %s\n", prefix, dateString, event.filename, event.line, event.caller, strings.ToUpper(event.level.String())[0], event.msg)
 	fileLogger.LogEvent(&event)
 	fileLogger.Flush()
 	logData, err = ioutil.ReadFile(filename)
@@ -138,7 +138,7 @@ func TestFileLogger(t *testing.T) {
 	assert.Equal(t, expected, string(logData))
 
 	// Should fail to rotate
-	expected = expected + fmt.Sprintf("%s%s %s:%d:%s [%c] %s\n", prefix, dateString, event.filename, event.line, event.caller, strings.ToUpper(event.level.String())[0], event.msg)
+	expected += fmt.Sprintf("%s%s %s:%d:%s [%c] %s\n", prefix, dateString, event.filename, event.line, event.caller, strings.ToUpper(event.level.String())[0], event.msg)
 	fileLogger.LogEvent(&event)
 	fileLogger.Flush()
 	logData, err = ioutil.ReadFile(filename)
@@ -188,7 +188,7 @@ func TestCompressFileLogger(t *testing.T) {
 	assert.Equal(t, expected, string(logData))
 
 	event.level = WARN
-	expected = expected + fmt.Sprintf("%s%s %s:%d:%s [%c] %s\n", prefix, dateString, event.filename, event.line, event.caller, strings.ToUpper(event.level.String())[0], event.msg)
+	expected += fmt.Sprintf("%s%s %s:%d:%s [%c] %s\n", prefix, dateString, event.filename, event.line, event.caller, strings.ToUpper(event.level.String())[0], event.msg)
 	fileLogger.LogEvent(&event)
 	fileLogger.Flush()
 	logData, err = ioutil.ReadFile(filename)
diff --git a/modules/log/flags.go b/modules/log/flags.go
index 928d42b965..992fc62ddb 100644
--- a/modules/log/flags.go
+++ b/modules/log/flags.go
@@ -57,7 +57,7 @@ func FlagsFromString(from string) int {
 	for _, flag := range strings.Split(strings.ToLower(from), ",") {
 		f, ok := flagFromString[strings.TrimSpace(flag)]
 		if ok {
-			flags = flags | f
+			flags |= f
 		}
 	}
 	return flags
diff --git a/modules/log/log.go b/modules/log/log.go
index 8698e9eed3..0ca0f3adc5 100644
--- a/modules/log/log.go
+++ b/modules/log/log.go
@@ -218,7 +218,7 @@ func (l *LoggerAsWriter) Write(p []byte) (int, error) {
 func (l *LoggerAsWriter) Log(msg string) {
 	for _, logger := range l.ourLoggers {
 		// Set the skip to reference the call just above this
-		logger.Log(1, l.level, msg)
+		_ = logger.Log(1, l.level, msg)
 	}
 }
 
diff --git a/modules/log/smtp.go b/modules/log/smtp.go
index f77d716d94..f912299a73 100644
--- a/modules/log/smtp.go
+++ b/modules/log/smtp.go
@@ -11,10 +11,6 @@ import (
 	"strings"
 )
 
-const (
-	subjectPhrase = "Diagnostic message from server"
-)
-
 type smtpWriter struct {
 	owner *SMTPLogger
 }
diff --git a/modules/log/writer.go b/modules/log/writer.go
index 22ef0b9047..2503f04d76 100644
--- a/modules/log/writer.go
+++ b/modules/log/writer.go
@@ -252,10 +252,7 @@ func (logger *WriterLogger) Match(event *Event) bool {
 		mode: removeColor,
 	}).Write([]byte(event.msg))
 	msg = baw
-	if logger.regexp.Match(msg) {
-		return true
-	}
-	return false
+	return logger.regexp.Match(msg)
 }
 
 // Close the base logger
diff --git a/modules/mailer/mailer.go b/modules/mailer/mailer.go
index 411d6eafd8..d19ae7b2f4 100644
--- a/modules/mailer/mailer.go
+++ b/modules/mailer/mailer.go
@@ -258,15 +258,12 @@ func (s *dummySender) Send(from string, to []string, msg io.WriterTo) error {
 }
 
 func processMailQueue() {
-	for {
-		select {
-		case msg := <-mailQueue:
-			log.Trace("New e-mail sending request %s: %s", msg.GetHeader("To"), msg.Info)
-			if err := gomail.Send(Sender, msg.Message); err != nil {
-				log.Error("Failed to send emails %s: %s - %v", msg.GetHeader("To"), msg.Info, err)
-			} else {
-				log.Trace("E-mails sent %s: %s", msg.GetHeader("To"), msg.Info)
-			}
+	for msg := range mailQueue {
+		log.Trace("New e-mail sending request %s: %s", msg.GetHeader("To"), msg.Info)
+		if err := gomail.Send(Sender, msg.Message); err != nil {
+			log.Error("Failed to send emails %s: %s - %v", msg.GetHeader("To"), msg.Info, err)
+		} else {
+			log.Trace("E-mails sent %s: %s", msg.GetHeader("To"), msg.Info)
 		}
 	}
 }
diff --git a/modules/markup/html.go b/modules/markup/html.go
index 91913b0679..dbfc8dbe85 100644
--- a/modules/markup/html.go
+++ b/modules/markup/html.go
@@ -108,24 +108,6 @@ func FindAllMentions(content string) []string {
 	return ret
 }
 
-// cutoutVerbosePrefix cutouts URL prefix including sub-path to
-// return a clean unified string of request URL path.
-func cutoutVerbosePrefix(prefix string) string {
-	if len(prefix) == 0 || prefix[0] != '/' {
-		return prefix
-	}
-	count := 0
-	for i := 0; i < len(prefix); i++ {
-		if prefix[i] == '/' {
-			count++
-		}
-		if count >= 3+setting.AppSubURLDepth {
-			return prefix[:i]
-		}
-	}
-	return prefix
-}
-
 // IsSameDomain checks if given url string has the same hostname as current Gitea instance
 func IsSameDomain(s string) bool {
 	if strings.HasPrefix(s, "/") {
@@ -146,7 +128,7 @@ type postProcessError struct {
 }
 
 func (p *postProcessError) Error() string {
-	return "PostProcess: " + p.context + ", " + p.Error()
+	return "PostProcess: " + p.context + ", " + p.err.Error()
 }
 
 type processor func(ctx *postProcessCtx, node *html.Node)
@@ -304,20 +286,6 @@ func (ctx *postProcessCtx) visitNode(node *html.Node) {
 	// ignore everything else
 }
 
-func (ctx *postProcessCtx) visitNodeForShortLinks(node *html.Node) {
-	switch node.Type {
-	case html.TextNode:
-		shortLinkProcessorFull(ctx, node, true)
-	case html.ElementNode:
-		if node.Data == "code" || node.Data == "pre" || node.Data == "a" {
-			return
-		}
-		for n := node.FirstChild; n != nil; n = n.NextSibling {
-			ctx.visitNodeForShortLinks(n)
-		}
-	}
-}
-
 // textNode runs the passed node through various processors, in order to handle
 // all kinds of special links handled by the post-processing.
 func (ctx *postProcessCtx) textNode(node *html.Node) {
diff --git a/modules/markup/html_internal_test.go b/modules/markup/html_internal_test.go
index 135a8e103c..10bc4973cd 100644
--- a/modules/markup/html_internal_test.go
+++ b/modules/markup/html_internal_test.go
@@ -29,11 +29,6 @@ func numericIssueLink(baseURL string, index int) string {
 	return link(util.URLJoin(baseURL, strconv.Itoa(index)), fmt.Sprintf("#%d", index))
 }
 
-// urlContentsLink an HTML link whose contents is the target URL
-func urlContentsLink(href string) string {
-	return link(href, href)
-}
-
 // link an HTML link
 func link(href, contents string) string {
 	return fmt.Sprintf("<a href=\"%s\">%s</a>", href, contents)
diff --git a/modules/notification/ui/ui.go b/modules/notification/ui/ui.go
index a31591c2a7..22089158f5 100644
--- a/modules/notification/ui/ui.go
+++ b/modules/notification/ui/ui.go
@@ -35,12 +35,9 @@ func NewNotifier() base.Notifier {
 }
 
 func (ns *notificationService) Run() {
-	for {
-		select {
-		case opts := <-ns.issueQueue:
-			if err := models.CreateOrUpdateIssueNotifications(opts.issue, opts.notificationAuthorID); err != nil {
-				log.Error("Was unable to create issue notification: %v", err)
-			}
+	for opts := range ns.issueQueue {
+		if err := models.CreateOrUpdateIssueNotifications(opts.issue, opts.notificationAuthorID); err != nil {
+			log.Error("Was unable to create issue notification: %v", err)
 		}
 	}
 }
diff --git a/modules/pprof/pprof.go b/modules/pprof/pprof.go
index b63904e713..80ad67be3a 100644
--- a/modules/pprof/pprof.go
+++ b/modules/pprof/pprof.go
@@ -9,6 +9,8 @@ import (
 	"io/ioutil"
 	"runtime"
 	"runtime/pprof"
+
+	"code.gitea.io/gitea/modules/log"
 )
 
 // DumpMemProfileForUsername dumps a memory profile at pprofDataPath as memprofile_<username>_<temporary id>
@@ -30,9 +32,15 @@ func DumpCPUProfileForUsername(pprofDataPath, username string) (func(), error) {
 		return nil, err
 	}
 
-	pprof.StartCPUProfile(f)
+	err = pprof.StartCPUProfile(f)
+	if err != nil {
+		log.Fatal("StartCPUProfile: %v", err)
+	}
 	return func() {
 		pprof.StopCPUProfile()
-		f.Close()
+		err = f.Close()
+		if err != nil {
+			log.Fatal("StopCPUProfile Close: %v", err)
+		}
 	}, nil
 }
diff --git a/modules/repofiles/delete.go b/modules/repofiles/delete.go
index 09a4dbb44c..91910fa860 100644
--- a/modules/repofiles/delete.go
+++ b/modules/repofiles/delete.go
@@ -53,11 +53,9 @@ func DeleteRepoFile(repo *models.Repository, doer *models.User, opts *DeleteRepo
 				BranchName: opts.NewBranch,
 			}
 		}
-	} else {
-		if protected, _ := repo.IsProtectedBranchForPush(opts.OldBranch, doer); protected {
-			return nil, models.ErrUserCannotCommit{
-				UserName: doer.LowerName,
-			}
+	} else if protected, _ := repo.IsProtectedBranchForPush(opts.OldBranch, doer); protected {
+		return nil, models.ErrUserCannotCommit{
+			UserName: doer.LowerName,
 		}
 	}
 
@@ -74,10 +72,10 @@ func DeleteRepoFile(repo *models.Repository, doer *models.User, opts *DeleteRepo
 	author, committer := GetAuthorAndCommitterUsers(opts.Committer, opts.Author, doer)
 
 	t, err := NewTemporaryUploadRepository(repo)
-	defer t.Close()
 	if err != nil {
 		return nil, err
 	}
+	defer t.Close()
 	if err := t.Clone(opts.OldBranch); err != nil {
 		return nil, err
 	}
diff --git a/modules/repofiles/file.go b/modules/repofiles/file.go
index de3ee71dba..70fd57bba0 100644
--- a/modules/repofiles/file.go
+++ b/modules/repofiles/file.go
@@ -86,7 +86,7 @@ func GetAuthorAndCommitterUsers(author, committer *IdentityOptions, doer *models
 	// If only one of the two are provided, we set both of them to it.
 	// If neither are provided, both are the doer.
 	if committer != nil && committer.Email != "" {
-		if doer != nil && strings.ToLower(doer.Email) == strings.ToLower(committer.Email) {
+		if doer != nil && strings.EqualFold(doer.Email, committer.Email) {
 			committerUser = doer // the committer is the doer, so will use their user object
 			if committer.Name != "" {
 				committerUser.FullName = committer.Name
@@ -99,7 +99,7 @@ func GetAuthorAndCommitterUsers(author, committer *IdentityOptions, doer *models
 		}
 	}
 	if author != nil && author.Email != "" {
-		if doer != nil && strings.ToLower(doer.Email) == strings.ToLower(author.Email) {
+		if doer != nil && strings.EqualFold(doer.Email, author.Email) {
 			authorUser = doer // the author is the doer, so will use their user object
 			if authorUser.Name != "" {
 				authorUser.FullName = author.Name
diff --git a/modules/repofiles/tree.go b/modules/repofiles/tree.go
index 4eb54a2598..318a5d152d 100644
--- a/modules/repofiles/tree.go
+++ b/modules/repofiles/tree.go
@@ -16,6 +16,9 @@ import (
 // GetTreeBySHA get the GitTreeResponse of a repository using a sha hash.
 func GetTreeBySHA(repo *models.Repository, sha string, page, perPage int, recursive bool) (*api.GitTreeResponse, error) {
 	gitRepo, err := git.OpenRepository(repo.RepoPath())
+	if err != nil {
+		return nil, err
+	}
 	gitTree, err := gitRepo.GetTree(sha)
 	if err != nil || gitTree == nil {
 		return nil, models.ErrSHANotFound{
@@ -39,12 +42,12 @@ func GetTreeBySHA(repo *models.Repository, sha string, page, perPage int, recurs
 
 	// 51 is len(sha1) + len("/git/blobs/"). 40 + 11.
 	blobURL := make([]byte, apiURLLen+51)
-	copy(blobURL[:], apiURL)
+	copy(blobURL, apiURL)
 	copy(blobURL[apiURLLen:], "/git/blobs/")
 
 	// 51 is len(sha1) + len("/git/trees/"). 40 + 11.
 	treeURL := make([]byte, apiURLLen+51)
-	copy(treeURL[:], apiURL)
+	copy(treeURL, apiURL)
 	copy(treeURL[apiURLLen:], "/git/trees/")
 
 	// 40 is the size of the sha1 hash in hexadecimal format.
@@ -83,10 +86,10 @@ func GetTreeBySHA(repo *models.Repository, sha string, page, perPage int, recurs
 
 		if entries[e].IsDir() {
 			copy(treeURL[copyPos:], entries[e].ID.String())
-			tree.Entries[i].URL = string(treeURL[:])
+			tree.Entries[i].URL = string(treeURL)
 		} else {
 			copy(blobURL[copyPos:], entries[e].ID.String())
-			tree.Entries[i].URL = string(blobURL[:])
+			tree.Entries[i].URL = string(blobURL)
 		}
 	}
 	return tree, nil
diff --git a/modules/repofiles/update.go b/modules/repofiles/update.go
index 569c89ac51..f011017a5e 100644
--- a/modules/repofiles/update.go
+++ b/modules/repofiles/update.go
@@ -99,6 +99,10 @@ func detectEncodingAndBOM(entry *git.TreeEntry, repo *models.Repository) (string
 	}
 
 	result, n, err := transform.String(charsetEncoding.NewDecoder(), string(buf))
+	if err != nil {
+		// return default
+		return "UTF-8", false
+	}
 
 	if n > 2 {
 		return encoding, bytes.Equal([]byte(result)[0:3], base.UTF8BOM)
@@ -135,10 +139,8 @@ func CreateOrUpdateRepoFile(repo *models.Repository, doer *models.User, opts *Up
 		if err != nil && !git.IsErrBranchNotExist(err) {
 			return nil, err
 		}
-	} else {
-		if protected, _ := repo.IsProtectedBranchForPush(opts.OldBranch, doer); protected {
-			return nil, models.ErrUserCannotCommit{UserName: doer.LowerName}
-		}
+	} else if protected, _ := repo.IsProtectedBranchForPush(opts.OldBranch, doer); protected {
+		return nil, models.ErrUserCannotCommit{UserName: doer.LowerName}
 	}
 
 	// If FromTreePath is not set, set it to the opts.TreePath
@@ -166,10 +168,10 @@ func CreateOrUpdateRepoFile(repo *models.Repository, doer *models.User, opts *Up
 	author, committer := GetAuthorAndCommitterUsers(opts.Committer, opts.Author, doer)
 
 	t, err := NewTemporaryUploadRepository(repo)
-	defer t.Close()
 	if err != nil {
-		return nil, err
+		log.Error("%v", err)
 	}
+	defer t.Close()
 	if err := t.Clone(opts.OldBranch); err != nil {
 		return nil, err
 	}
diff --git a/modules/repofiles/upload.go b/modules/repofiles/upload.go
index 5f428c3139..2da101c64d 100644
--- a/modules/repofiles/upload.go
+++ b/modules/repofiles/upload.go
@@ -57,10 +57,10 @@ func UploadRepoFiles(repo *models.Repository, doer *models.User, opts *UploadRep
 	}
 
 	t, err := NewTemporaryUploadRepository(repo)
-	defer t.Close()
 	if err != nil {
 		return err
 	}
+	defer t.Close()
 	if err := t.Clone(opts.OldBranch); err != nil {
 		return err
 	}
@@ -108,10 +108,8 @@ func UploadRepoFiles(repo *models.Repository, doer *models.User, opts *UploadRep
 			}
 			infos[i] = uploadInfo
 
-		} else {
-			if objectHash, err = t.HashObject(file); err != nil {
-				return err
-			}
+		} else if objectHash, err = t.HashObject(file); err != nil {
+			return err
 		}
 
 		// Add the object to the index
diff --git a/modules/repofiles/verification.go b/modules/repofiles/verification.go
index be56f9b8b8..9fc084daaf 100644
--- a/modules/repofiles/verification.go
+++ b/modules/repofiles/verification.go
@@ -20,10 +20,8 @@ func GetPayloadCommitVerification(commit *git.Commit) *structs.PayloadCommitVeri
 	}
 	if verification.Reason != "" {
 		verification.Reason = commitVerification.Reason
-	} else {
-		if verification.Verified {
-			verification.Reason = "unsigned"
-		}
+	} else if verification.Verified {
+		verification.Reason = "unsigned"
 	}
 	return verification
 }
diff --git a/modules/session/virtual.go b/modules/session/virtual.go
index b90f03417a..b8ddd2f71b 100644
--- a/modules/session/virtual.go
+++ b/modules/session/virtual.go
@@ -21,10 +21,8 @@ import (
 
 // VirtualSessionProvider represents a shadowed session provider implementation.
 type VirtualSessionProvider struct {
-	lock        sync.RWMutex
-	maxlifetime int64
-	rootPath    string
-	provider    session.Provider
+	lock     sync.RWMutex
+	provider session.Provider
 }
 
 // Init initializes the cookie session provider with given root path.
diff --git a/modules/setting/log.go b/modules/setting/log.go
index 9f4bbf9d87..5e2d2d769d 100644
--- a/modules/setting/log.go
+++ b/modules/setting/log.go
@@ -150,8 +150,6 @@ func generateNamedLogger(key string, options defaultLogOptions) *LogDescription
 
 	sections := strings.Split(Cfg.Section("log").Key(strings.ToUpper(key)).MustString(""), ",")
 
-	//description.Configs = make([]string, len(description.Sections))
-
 	for i := 0; i < len(sections); i++ {
 		sections[i] = strings.TrimSpace(sections[i])
 	}
@@ -167,7 +165,10 @@ func generateNamedLogger(key string, options defaultLogOptions) *LogDescription
 
 		provider, config, levelName := generateLogConfig(sec, name, options)
 
-		log.NewNamedLogger(key, options.bufferLength, name, provider, config)
+		if err := log.NewNamedLogger(key, options.bufferLength, name, provider, config); err != nil {
+			// Maybe panic here?
+			log.Error("Could not create new named logger: %v", err.Error())
+		}
 
 		description.SubLogDescriptions = append(description.SubLogDescriptions, SubLogDescription{
 			Name:     name,
@@ -242,7 +243,10 @@ func newLogService() {
 	}
 
 	if !useConsole {
-		log.DelLogger("console")
+		err := log.DelLogger("console")
+		if err != nil {
+			log.Fatal("DelLogger: %v", err)
+		}
 	}
 
 	for _, name := range sections {
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index ff53e9a375..b550836bc1 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -545,13 +545,14 @@ func NewContext() {
 	AppName = Cfg.Section("").Key("APP_NAME").MustString("Gitea: Git with a cup of tea")
 
 	Protocol = HTTP
-	if sec.Key("PROTOCOL").String() == "https" {
+	switch sec.Key("PROTOCOL").String() {
+	case "https":
 		Protocol = HTTPS
 		CertFile = sec.Key("CERT_FILE").String()
 		KeyFile = sec.Key("KEY_FILE").String()
-	} else if sec.Key("PROTOCOL").String() == "fcgi" {
+	case "fcgi":
 		Protocol = FCGI
-	} else if sec.Key("PROTOCOL").String() == "unix" {
+	case "unix":
 		Protocol = UnixSocket
 		UnixSocketPermissionRaw := sec.Key("UNIX_SOCKET_PERMISSION").MustString("666")
 		UnixSocketPermissionParsed, err := strconv.ParseUint(UnixSocketPermissionRaw, 8, 32)
diff --git a/modules/ssh/ssh.go b/modules/ssh/ssh.go
index 98ff50bfec..c5251ef23a 100644
--- a/modules/ssh/ssh.go
+++ b/modules/ssh/ssh.go
@@ -37,7 +37,10 @@ func cleanCommand(cmd string) string {
 func handleServerConn(keyID string, chans <-chan ssh.NewChannel) {
 	for newChan := range chans {
 		if newChan.ChannelType() != "session" {
-			newChan.Reject(ssh.UnknownChannelType, "unknown channel type")
+			err := newChan.Reject(ssh.UnknownChannelType, "unknown channel type")
+			if err != nil {
+				log.Error("Error rejecting channel: %v", err)
+			}
 			continue
 		}
 
@@ -48,7 +51,11 @@ func handleServerConn(keyID string, chans <-chan ssh.NewChannel) {
 		}
 
 		go func(in <-chan *ssh.Request) {
-			defer ch.Close()
+			defer func() {
+				if err = ch.Close(); err != nil {
+					log.Error("Close: %v", err)
+				}
+			}()
 			for req := range in {
 				payload := cleanCommand(string(req.Payload))
 				switch req.Type {
@@ -87,17 +94,34 @@ func handleServerConn(keyID string, chans <-chan ssh.NewChannel) {
 						return
 					}
 
-					req.Reply(true, nil)
-					go io.Copy(input, ch)
-					io.Copy(ch, stdout)
-					io.Copy(ch.Stderr(), stderr)
+					err = req.Reply(true, nil)
+					if err != nil {
+						log.Error("SSH: Reply: %v", err)
+					}
+					go func() {
+						_, err = io.Copy(input, ch)
+						if err != nil {
+							log.Error("SSH: Copy: %v", err)
+						}
+					}()
+					_, err = io.Copy(ch, stdout)
+					if err != nil {
+						log.Error("SSH: Copy: %v", err)
+					}
+					_, err = io.Copy(ch.Stderr(), stderr)
+					if err != nil {
+						log.Error("SSH: Copy: %v", err)
+					}
 
 					if err = cmd.Wait(); err != nil {
 						log.Error("SSH: Wait: %v", err)
 						return
 					}
 
-					ch.SendRequest("exit-status", false, []byte{0, 0, 0, 0})
+					_, err = ch.SendRequest("exit-status", false, []byte{0, 0, 0, 0})
+					if err != nil {
+						log.Error("SSH: SendRequest: %v", err)
+					}
 					return
 				default:
 				}
@@ -203,7 +227,11 @@ func GenKeyPair(keyPath string) error {
 	if err != nil {
 		return err
 	}
-	defer f.Close()
+	defer func() {
+		if err = f.Close(); err != nil {
+			log.Error("Close: %v", err)
+		}
+	}()
 
 	if err := pem.Encode(f, privateKeyPEM); err != nil {
 		return err
@@ -220,7 +248,11 @@ func GenKeyPair(keyPath string) error {
 	if err != nil {
 		return err
 	}
-	defer p.Close()
+	defer func() {
+		if err = p.Close(); err != nil {
+			log.Error("Close: %v", err)
+		}
+	}()
 	_, err = p.Write(public)
 	return err
 }
diff --git a/modules/structs/user_search.go b/modules/structs/user_search.go
deleted file mode 100644
index 1650cf736a..0000000000
--- a/modules/structs/user_search.go
+++ /dev/null
@@ -1,5 +0,0 @@
-package structs
-
-type searchUsersResponse struct {
-	Users []*User `json:"data"`
-}
diff --git a/modules/structs/utils.go b/modules/structs/utils.go
index 1b9d689562..aaeb653d03 100644
--- a/modules/structs/utils.go
+++ b/modules/structs/utils.go
@@ -4,12 +4,6 @@
 
 package structs
 
-import (
-	"net/http"
-)
-
-var jsonHeader = http.Header{"content-type": []string{"application/json"}}
-
 // Bool return address of bool value
 func Bool(v bool) *bool {
 	return &v
diff --git a/modules/templates/dynamic.go b/modules/templates/dynamic.go
index dbd75221d2..d7c04ccb09 100644
--- a/modules/templates/dynamic.go
+++ b/modules/templates/dynamic.go
@@ -83,12 +83,15 @@ func Mailer() *template.Template {
 					continue
 				}
 
-				templates.New(
+				_, err = templates.New(
 					strings.TrimSuffix(
 						filePath,
 						".tmpl",
 					),
 				).Parse(string(content))
+				if err != nil {
+					log.Warn("Failed to parse template %v", err)
+				}
 			}
 		}
 	}
@@ -113,12 +116,15 @@ func Mailer() *template.Template {
 					continue
 				}
 
-				templates.New(
+				_, err = templates.New(
 					strings.TrimSuffix(
 						filePath,
 						".tmpl",
 					),
 				).Parse(string(content))
+				if err != nil {
+					log.Warn("Failed to parse template %v", err)
+				}
 			}
 		}
 	}
diff --git a/modules/templates/helper.go b/modules/templates/helper.go
index ef4a68add0..c4551bb4be 100644
--- a/modules/templates/helper.go
+++ b/modules/templates/helper.go
@@ -343,7 +343,7 @@ func ReplaceLeft(s, oldS, newS string) string {
 
 	// allocating space for the new string
 	curLen := n*newLen + len(s[i:])
-	replacement := make([]byte, curLen, curLen)
+	replacement := make([]byte, curLen)
 
 	j := 0
 	for ; j < n*newLen; j += newLen {
diff --git a/modules/user/user_test.go b/modules/user/user_test.go
index ae7460281f..fadcbde7bf 100644
--- a/modules/user/user_test.go
+++ b/modules/user/user_test.go
@@ -13,7 +13,7 @@ func getWhoamiOutput() (string, error) {
 	if err != nil {
 		return "", err
 	}
-	return strings.TrimSpace(string(output[:])), nil
+	return strings.TrimSpace(string(output)), nil
 }
 
 func TestCurrentUsername(t *testing.T) {
diff --git a/modules/validation/binding_test.go b/modules/validation/binding_test.go
index 7bc41ac395..f55b09266d 100644
--- a/modules/validation/binding_test.go
+++ b/modules/validation/binding_test.go
@@ -26,12 +26,6 @@ type (
 		expectedErrors binding.Errors
 	}
 
-	handlerFunc func(interface{}, ...interface{}) macaron.Handler
-
-	modeler interface {
-		Model() string
-	}
-
 	TestForm struct {
 		BranchName string `form:"BranchName" binding:"GitRefName"`
 		URL        string `form:"ValidUrl" binding:"ValidUrl"`