Handle and propagate errors when checking if paths are Dirs, Files or Exist (#13186)

* Ensure errors from IsDir propagate

* Handle errors when checking IsFile

* Handle and propagate errors from IsExist

* Update modules/templates/static.go

* Update modules/templates/static.go

* Return after ctx.ServerError

* Apply suggestions from code review

* Fix tests

The previous merge managed to break repo_form.go

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lauris BH <lauris@nix.lv>

16 files changed, 202 insertions, 42 deletions

diff --git a/modules/auth/repo_form.go b/modules/auth/repo_form.go
index f27812bb1b..2d6f89b6ed 100644
--- a/modules/auth/repo_form.go
+++ b/modules/auth/repo_form.go
@@ -10,13 +10,14 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/routers/utils"
 
 	"gitea.com/macaron/binding"
 	"gitea.com/macaron/macaron"
-	"github.com/unknwon/com"
 )
 
 // _______________________________________    _________.______________________ _______________.___.
@@ -107,8 +108,15 @@ func ParseRemoteAddr(remoteAddr, authUsername, authPassword string, user *models
 		}
 	} else if !user.CanImportLocal() {
 		return "", models.ErrInvalidCloneAddr{IsPermissionDenied: true}
-	} else if !com.IsDir(remoteAddr) {
-		return "", models.ErrInvalidCloneAddr{IsInvalidPath: true}
+	} else {
+		isDir, err := util.IsDir(remoteAddr)
+		if err != nil {
+			log.Error("Unable to check if %s is a directory: %v", remoteAddr, err)
+			return "", err
+		}
+		if !isDir {
+			return "", models.ErrInvalidCloneAddr{IsInvalidPath: true}
+		}
 	}
 
 	return remoteAddr, nil
diff --git a/modules/git/hook.go b/modules/git/hook.go
index 2de36dbdef..c23fbf8aa1 100644
--- a/modules/git/hook.go
+++ b/modules/git/hook.go
@@ -13,7 +13,6 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/modules/util"
-	"github.com/unknwon/com"
 )
 
 // hookNames is a list of Git server hooks' name that are supported.
@@ -129,7 +128,12 @@ const (
 func SetUpdateHook(repoPath, content string) (err error) {
 	log("Setting update hook: %s", repoPath)
 	hookPath := path.Join(repoPath, HookPathUpdate)
-	if com.IsExist(hookPath) {
+	isExist, err := util.IsExist(hookPath)
+	if err != nil {
+		log("Unable to check if %s exists. Error: %v", hookPath, err)
+		return err
+	}
+	if isExist {
 		err = util.Remove(hookPath)
 	} else {
 		err = os.MkdirAll(path.Dir(hookPath), os.ModePerm)
diff --git a/modules/options/dynamic.go b/modules/options/dynamic.go
index 20dde11dc3..060ca12bb0 100644
--- a/modules/options/dynamic.go
+++ b/modules/options/dynamic.go
@@ -11,7 +11,9 @@ import (
 	"io/ioutil"
 	"path"
 
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/unknwon/com"
 )
@@ -32,7 +34,11 @@ func Dir(name string) ([]string, error) {
 
 	customDir := path.Join(setting.CustomPath, "options", name)
 
-	if com.IsDir(customDir) {
+	isDir, err := util.IsDir(customDir)
+	if err != nil {
+		return []string{}, fmt.Errorf("Unabe to check if custom directory %s is a directory. %v", customDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir, true)
 
 		if err != nil {
@@ -44,7 +50,11 @@ func Dir(name string) ([]string, error) {
 
 	staticDir := path.Join(setting.StaticRootPath, "options", name)
 
-	if com.IsDir(staticDir) {
+	isDir, err = util.IsDir(staticDir)
+	if err != nil {
+		return []string{}, fmt.Errorf("Unabe to check if static directory %s is a directory. %v", staticDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(staticDir, true)
 
 		if err != nil {
@@ -86,13 +96,21 @@ func Labels(name string) ([]byte, error) {
 func fileFromDir(name string) ([]byte, error) {
 	customPath := path.Join(setting.CustomPath, "options", name)
 
-	if com.IsFile(customPath) {
+	isFile, err := util.IsFile(customPath)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", customPath, err)
+	}
+	if isFile {
 		return ioutil.ReadFile(customPath)
 	}
 
 	staticPath := path.Join(setting.StaticRootPath, "options", name)
 
-	if com.IsFile(staticPath) {
+	isFile, err = util.IsFile(staticPath)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", staticPath, err)
+	}
+	if isFile {
 		return ioutil.ReadFile(staticPath)
 	}
 
diff --git a/modules/options/static.go b/modules/options/static.go
index 39f56f42f4..ff1e6b2332 100644
--- a/modules/options/static.go
+++ b/modules/options/static.go
@@ -11,7 +11,9 @@ import (
 	"io/ioutil"
 	"path"
 
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/unknwon/com"
 )
@@ -31,8 +33,11 @@ func Dir(name string) ([]string, error) {
 	)
 
 	customDir := path.Join(setting.CustomPath, "options", name)
-
-	if com.IsDir(customDir) {
+	isDir, err := util.IsDir(customDir)
+	if err != nil {
+		return []string{}, fmt.Errorf("Failed to check if custom directory %s is a directory. %v", err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir, true)
 
 		if err != nil {
@@ -100,7 +105,11 @@ func Labels(name string) ([]byte, error) {
 func fileFromDir(name string) ([]byte, error) {
 	customPath := path.Join(setting.CustomPath, "options", name)
 
-	if com.IsFile(customPath) {
+	isFile, err := util.IsFile(customPath)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", customPath, err)
+	}
+	if isFile {
 		return ioutil.ReadFile(customPath)
 	}
 
diff --git a/modules/repository/adopt.go b/modules/repository/adopt.go
index 22cd6dd91f..0302119630 100644
--- a/modules/repository/adopt.go
+++ b/modules/repository/adopt.go
@@ -16,7 +16,6 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
 	"github.com/gobwas/glob"
-	"github.com/unknwon/com"
 )
 
 // AdoptRepository adopts a repository for the user/organization.
@@ -49,7 +48,12 @@ func AdoptRepository(doer, u *models.User, opts models.CreateRepoOptions) (*mode
 
 	if err := models.WithTx(func(ctx models.DBContext) error {
 		repoPath := models.RepoPath(u.Name, repo.Name)
-		if !com.IsExist(repoPath) {
+		isExist, err := util.IsExist(repoPath)
+		if err != nil {
+			log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+			return err
+		}
+		if !isExist {
 			return models.ErrRepoNotExist{
 				OwnerName: u.Name,
 				Name:      repo.Name,
@@ -91,7 +95,12 @@ func DeleteUnadoptedRepository(doer, u *models.User, repoName string) error {
 	}
 
 	repoPath := models.RepoPath(u.Name, repoName)
-	if !com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return err
+	}
+	if !isExist {
 		return models.ErrRepoNotExist{
 			OwnerName: u.Name,
 			Name:      repoName,
diff --git a/modules/repository/check.go b/modules/repository/check.go
index 274576c348..d13ddbb0b0 100644
--- a/modules/repository/check.go
+++ b/modules/repository/check.go
@@ -13,8 +13,8 @@ import (
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
 
-	"github.com/unknwon/com"
 	"xorm.io/builder"
 )
 
@@ -114,7 +114,11 @@ func gatherMissingRepoRecords(ctx context.Context) ([]*models.Repository, error)
 				return models.ErrCancelledf("during gathering missing repo records before checking %s", repo.FullName())
 			default:
 			}
-			if !com.IsDir(repo.RepoPath()) {
+			isDir, err := util.IsDir(repo.RepoPath())
+			if err != nil {
+				return fmt.Errorf("Unable to check dir for %s. %w", repo.FullName(), err)
+			}
+			if !isDir {
 				repos = append(repos, repo)
 			}
 			return nil
diff --git a/modules/repository/create.go b/modules/repository/create.go
index 1408637815..1f7145ee2a 100644
--- a/modules/repository/create.go
+++ b/modules/repository/create.go
@@ -13,8 +13,6 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
-
-	"github.com/unknwon/com"
 )
 
 // CreateRepository creates a repository for the user/organization.
@@ -58,7 +56,12 @@ func CreateRepository(doer, u *models.User, opts models.CreateRepoOptions) (*mod
 		}
 
 		repoPath := models.RepoPath(u.Name, repo.Name)
-		if com.IsExist(repoPath) {
+		isExist, err := util.IsExist(repoPath)
+		if err != nil {
+			log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+			return err
+		}
+		if isExist {
 			// repo already exists - We have two or three options.
 			// 1. We fail stating that the directory exists
 			// 2. We create the db repository to go with this data and adopt the git repo
diff --git a/modules/repository/generate.go b/modules/repository/generate.go
index 5d1ef72b6c..0142d689d1 100644
--- a/modules/repository/generate.go
+++ b/modules/repository/generate.go
@@ -19,7 +19,6 @@ import (
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/huandu/xstrings"
-	"github.com/unknwon/com"
 )
 
 type transformer struct {
@@ -252,7 +251,12 @@ func GenerateRepository(ctx models.DBContext, doer, owner *models.User, template
 	}
 
 	repoPath := generateRepo.RepoPath()
-	if com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return nil, err
+	}
+	if isExist {
 		return nil, models.ErrRepoFilesAlreadyExist{
 			Uname: generateRepo.OwnerName,
 			Name:  generateRepo.Name,
diff --git a/modules/repository/hooks.go b/modules/repository/hooks.go
index faf9c98f8a..aba5db6719 100644
--- a/modules/repository/hooks.go
+++ b/modules/repository/hooks.go
@@ -15,7 +15,6 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
-	"github.com/unknwon/com"
 
 	"xorm.io/builder"
 )
@@ -112,15 +111,27 @@ func CheckDelegateHooks(repoPath string) ([]string, error) {
 		newHookPath := filepath.Join(hookDir, hookName+".d", "gitea")
 
 		cont := false
-		if !com.IsExist(oldHookPath) {
+		isExist, err := util.IsExist(oldHookPath)
+		if err != nil {
+			results = append(results, fmt.Sprintf("unable to check if %s exists. Error: %v", oldHookPath, err))
+		}
+		if err == nil && !isExist {
 			results = append(results, fmt.Sprintf("old hook file %s does not exist", oldHookPath))
 			cont = true
 		}
-		if !com.IsExist(oldHookPath + ".d") {
+		isExist, err = util.IsExist(oldHookPath + ".d")
+		if err != nil {
+			results = append(results, fmt.Sprintf("unable to check if %s exists. Error: %v", oldHookPath+".d", err))
+		}
+		if err == nil && !isExist {
 			results = append(results, fmt.Sprintf("hooks directory %s does not exist", oldHookPath+".d"))
 			cont = true
 		}
-		if !com.IsExist(newHookPath) {
+		isExist, err = util.IsExist(newHookPath)
+		if err != nil {
+			results = append(results, fmt.Sprintf("unable to check if %s exists. Error: %v", newHookPath, err))
+		}
+		if err == nil && !isExist {
 			results = append(results, fmt.Sprintf("new hook file %s does not exist", newHookPath))
 			cont = true
 		}
diff --git a/modules/repository/init.go b/modules/repository/init.go
index 569069ee1f..37dc69a0a8 100644
--- a/modules/repository/init.go
+++ b/modules/repository/init.go
@@ -175,7 +175,12 @@ func initRepoCommit(tmpPath string, repo *models.Repository, u *models.User, def
 func checkInitRepository(owner, name string) (err error) {
 	// Somehow the directory could exist.
 	repoPath := models.RepoPath(owner, name)
-	if com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return err
+	}
+	if isExist {
 		return models.ErrRepoFilesAlreadyExist{
 			Uname: owner,
 			Name:  name,
@@ -192,7 +197,12 @@ func checkInitRepository(owner, name string) (err error) {
 }
 
 func adoptRepository(ctx models.DBContext, repoPath string, u *models.User, repo *models.Repository, opts models.CreateRepoOptions) (err error) {
-	if !com.IsExist(repoPath) {
+	isExist, err := util.IsExist(repoPath)
+	if err != nil {
+		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
+		return err
+	}
+	if !isExist {
 		return fmt.Errorf("adoptRepository: path does not already exist: %s", repoPath)
 	}
 
diff --git a/modules/setting/lfs.go b/modules/setting/lfs.go
index 5af80c2ab1..ab475bbeb4 100644
--- a/modules/setting/lfs.go
+++ b/modules/setting/lfs.go
@@ -13,8 +13,8 @@ import (
 	"code.gitea.io/gitea/modules/generate"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
 
-	"github.com/unknwon/com"
 	ini "gopkg.in/ini.v1"
 )
 
@@ -65,7 +65,11 @@ func newLFSService() {
 
 			// Save secret
 			cfg := ini.Empty()
-			if com.IsFile(CustomConf) {
+			isFile, err := util.IsFile(CustomConf)
+			if err != nil {
+				log.Error("Unable to check if %s is a file. Error: %v", CustomConf, err)
+			}
+			if isFile {
 				// Keeps custom settings if there is already something.
 				if err := cfg.Append(CustomConf); err != nil {
 					log.Error("Failed to load custom conf '%s': %v", CustomConf, err)
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index 708dc28233..79e7751905 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -25,6 +25,7 @@ import (
 	"code.gitea.io/gitea/modules/generate"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/user"
+	"code.gitea.io/gitea/modules/util"
 
 	shellquote "github.com/kballard/go-shellquote"
 	"github.com/unknwon/com"
@@ -498,7 +499,11 @@ func NewContext() {
 		createPIDFile(PIDFile)
 	}
 
-	if com.IsFile(CustomConf) {
+	isFile, err := util.IsFile(CustomConf)
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", CustomConf, err)
+	}
+	if isFile {
 		if err := Cfg.Append(CustomConf); err != nil {
 			log.Fatal("Failed to load custom conf '%s': %v", CustomConf, err)
 		}
@@ -739,7 +744,11 @@ func NewContext() {
 				return
 			}
 			cfg := ini.Empty()
-			if com.IsFile(CustomConf) {
+			isFile, err := util.IsFile(CustomConf)
+			if err != nil {
+				log.Error("Unable to check if %s is a file. Error: %v", CustomConf, err)
+			}
+			if isFile {
 				if err := cfg.Append(CustomConf); err != nil {
 					log.Error("failed to load custom conf %s: %v", CustomConf, err)
 					return
@@ -908,7 +917,10 @@ func NewContext() {
 	UI.SearchRepoDescription = Cfg.Section("ui").Key("SEARCH_REPO_DESCRIPTION").MustBool(true)
 	UI.UseServiceWorker = Cfg.Section("ui").Key("USE_SERVICE_WORKER").MustBool(true)
 
-	HasRobotsTxt = com.IsFile(path.Join(CustomPath, "robots.txt"))
+	HasRobotsTxt, err = util.IsFile(path.Join(CustomPath, "robots.txt"))
+	if err != nil {
+		log.Error("Unable to check if %s is a file. Error: %v", path.Join(CustomPath, "robots.txt"), err)
+	}
 
 	newMarkup()
 
@@ -1005,7 +1017,11 @@ func loadOrGenerateInternalToken(sec *ini.Section) string {
 
 		// Save secret
 		cfgSave := ini.Empty()
-		if com.IsFile(CustomConf) {
+		isFile, err := util.IsFile(CustomConf)
+		if err != nil {
+			log.Error("Unable to check if %s is a file. Error: %v", CustomConf, err)
+		}
+		if isFile {
 			// Keeps custom settings if there is already something.
 			if err := cfgSave.Append(CustomConf); err != nil {
 				log.Error("Failed to load custom conf '%s': %v", CustomConf, err)
diff --git a/modules/ssh/ssh.go b/modules/ssh/ssh.go
index 7a449dd41b..761164caa0 100644
--- a/modules/ssh/ssh.go
+++ b/modules/ssh/ssh.go
@@ -22,6 +22,7 @@ import (
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/gliderlabs/ssh"
 	"github.com/unknwon/com"
@@ -211,7 +212,11 @@ func Listen(host string, port int, ciphers []string, keyExchanges []string, macs
 	}
 
 	keyPath := filepath.Join(setting.AppDataPath, "ssh/gogs.rsa")
-	if !com.IsExist(keyPath) {
+	isExist, err := util.IsExist(keyPath)
+	if err != nil {
+		log.Fatal("Unable to check if %s exists. Error: %v", keyPath, err)
+	}
+	if !isExist {
 		filePath := filepath.Dir(keyPath)
 
 		if err := os.MkdirAll(filePath, os.ModePerm); err != nil {
@@ -225,7 +230,7 @@ func Listen(host string, port int, ciphers []string, keyExchanges []string, macs
 		log.Trace("New private key is generated: %s", keyPath)
 	}
 
-	err := srv.SetOption(ssh.HostKeyFile(keyPath))
+	err = srv.SetOption(ssh.HostKeyFile(keyPath))
 	if err != nil {
 		log.Error("Failed to set Host Key. %s", err)
 	}
diff --git a/modules/templates/dynamic.go b/modules/templates/dynamic.go
index bd1c4d06c5..5eda948034 100644
--- a/modules/templates/dynamic.go
+++ b/modules/templates/dynamic.go
@@ -15,6 +15,7 @@ import (
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"gitea.com/macaron/macaron"
 	"github.com/unknwon/com"
@@ -59,7 +60,11 @@ func Mailer() (*texttmpl.Template, *template.Template) {
 
 	staticDir := path.Join(setting.StaticRootPath, "templates", "mail")
 
-	if com.IsDir(staticDir) {
+	isDir, err := util.IsDir(staticDir)
+	if err != nil {
+		log.Warn("Unable to check if templates dir %s is a directory. Error: %v", staticDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(staticDir)
 
 		if err != nil {
@@ -84,7 +89,11 @@ func Mailer() (*texttmpl.Template, *template.Template) {
 
 	customDir := path.Join(setting.CustomPath, "templates", "mail")
 
-	if com.IsDir(customDir) {
+	isDir, err = util.IsDir(customDir)
+	if err != nil {
+		log.Warn("Unable to check if templates dir %s is a directory. Error: %v", customDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir)
 
 		if err != nil {
diff --git a/modules/templates/static.go b/modules/templates/static.go
index a3aff5e567..fd8e79a783 100644
--- a/modules/templates/static.go
+++ b/modules/templates/static.go
@@ -18,6 +18,7 @@ import (
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"gitea.com/macaron/macaron"
 	"github.com/unknwon/com"
@@ -77,8 +78,11 @@ func NewTemplateFileSystem() templateFileSystem {
 	}
 
 	customDir := path.Join(setting.CustomPath, "templates")
-
-	if com.IsDir(customDir) {
+	isDir, err := util.IsDir(customDir)
+	if err != nil {
+		log.Warn("Unable to check if templates dir %s is a directory. Error: %v", customDir, err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir)
 
 		if err != nil {
@@ -170,8 +174,11 @@ func Mailer() (*texttmpl.Template, *template.Template) {
 	}
 
 	customDir := path.Join(setting.CustomPath, "templates", "mail")
-
-	if com.IsDir(customDir) {
+	isDir, err := util.IsDir(customDir)
+	if err != nil {
+		log.Warn("Failed to check if custom directory %s is a directory. %v", err)
+	}
+	if isDir {
 		files, err := com.StatDir(customDir)
 
 		if err != nil {
diff --git a/modules/util/path.go b/modules/util/path.go
index 2b198eb6dc..fbcefb83b6 100644
--- a/modules/util/path.go
+++ b/modules/util/path.go
@@ -31,3 +31,42 @@ func GetDirectorySize(path string) (int64, error) {
 	})
 	return size, err
 }
+
+// IsDir returns true if given path is a directory,
+// or returns false when it's a file or does not exist.
+func IsDir(dir string) (bool, error) {
+	f, err := os.Stat(dir)
+	if err == nil {
+		return f.IsDir(), nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+// IsFile returns true if given path is a file,
+// or returns false when it's a directory or does not exist.
+func IsFile(filePath string) (bool, error) {
+	f, err := os.Stat(filePath)
+	if err == nil {
+		return !f.IsDir(), nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+// IsExist checks whether a file or directory exists.
+// It returns false when the file or directory does not exist.
+func IsExist(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil || os.IsExist(err) {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}