Disallow empty titles (#5785)

* add util method and tests

* make sure the title of an issue cannot be empty

* wiki title cannot be empty

* pull request title cannot be empty

* update to make use of the new util methof

7 files changed, 48 insertions, 3 deletions

diff --git a/cmd/cmd.go b/cmd/cmd.go
index d246d2599d..5a55ac318c 100644
--- a/cmd/cmd.go
+++ b/cmd/cmd.go
@@ -9,10 +9,11 @@ package cmd
 import (
 	"errors"
 	"fmt"
-	"strings"
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+
 	"github.com/urfave/cli"
 )
 
@@ -24,7 +25,7 @@ func argsSet(c *cli.Context, args ...string) error {
 			return errors.New(a + " is not set")
 		}
 
-		if len(strings.TrimSpace(c.String(a))) == 0 {
+		if util.IsEmptyString(a) {
 			return errors.New(a + " is required")
 		}
 	}
diff --git a/modules/util/util.go b/modules/util/util.go
index 5dcbe448fc..b2067c8df6 100644
--- a/modules/util/util.go
+++ b/modules/util/util.go
@@ -98,3 +98,8 @@ func Min(a, b int) int {
 	}
 	return a
 }
+
+// IsEmptyString checks if the provided string is empty
+func IsEmptyString(s string) bool {
+	return len(strings.TrimSpace(s)) == 0
+}
diff --git a/modules/util/util_test.go b/modules/util/util_test.go
index d9357ffa3d..3a2b4b71ff 100644
--- a/modules/util/util_test.go
+++ b/modules/util/util_test.go
@@ -77,3 +77,20 @@ func TestIsExternalURL(t *testing.T) {
 		assert.Equal(t, test.Expected, IsExternalURL(test.RawURL))
 	}
 }
+
+func TestIsEmptyString(t *testing.T) {
+
+	cases := []struct {
+		s        string
+		expected bool
+	}{
+		{"", true},
+		{" ", true},
+		{"   ", true},
+		{"  a", false},
+	}
+
+	for _, v := range cases {
+		assert.Equal(t, v.expected, IsEmptyString(v.s))
+	}
+}
diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index 0c32f3f5fd..85ce82084b 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -662,6 +662,7 @@ ext_issues.desc = Link to an external issue tracker.
 
 issues.desc = Organize bug reports, tasks and milestones.
 issues.new = New Issue
+issues.new.title_empty = Title cannot be empty
 issues.new.labels = Labels
 issues.new.no_label = No Label
 issues.new.clear_labels = Clear labels
diff --git a/routers/repo/issue.go b/routers/repo/issue.go
index 6c6c2612bf..8e0b22eb62 100644
--- a/routers/repo/issue.go
+++ b/routers/repo/issue.go
@@ -355,7 +355,7 @@ func setTemplateIfExists(ctx *context.Context, ctxDataKey string, possibleFiles
 	}
 }
 
-// NewIssue render createing issue page
+// NewIssue render creating issue page
 func NewIssue(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("repo.issues.new")
 	ctx.Data["PageIsIssueList"] = true
@@ -494,6 +494,11 @@ func NewIssuePost(ctx *context.Context, form auth.CreateIssueForm) {
 		return
 	}
 
+	if util.IsEmptyString(form.Title) {
+		ctx.RenderWithErr(ctx.Tr("repo.issues.new.title_empty"), tplIssueNew, form)
+		return
+	}
+
 	issue := &models.Issue{
 		RepoID:      repo.ID,
 		Title:       form.Title,
diff --git a/routers/repo/pull.go b/routers/repo/pull.go
index 688a033fdb..eecb4809a6 100644
--- a/routers/repo/pull.go
+++ b/routers/repo/pull.go
@@ -22,6 +22,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/notification"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/Unknwon/com"
 )
@@ -875,6 +876,16 @@ func CompareAndPullRequestPost(ctx *context.Context, form auth.CreateIssueForm)
 		return
 	}
 
+	if util.IsEmptyString(form.Title) {
+		PrepareCompareDiff(ctx, headUser, headRepo, headGitRepo, prInfo, baseBranch, headBranch)
+		if ctx.Written() {
+			return
+		}
+
+		ctx.RenderWithErr(ctx.Tr("repo.issues.new.title_empty"), tplComparePull, form)
+		return
+	}
+
 	patch, err := headGitRepo.GetPatch(prInfo.MergeBase, headBranch)
 	if err != nil {
 		ctx.ServerError("GetPatch", err)
diff --git a/routers/repo/wiki.go b/routers/repo/wiki.go
index 7e52129773..4cea3c890a 100644
--- a/routers/repo/wiki.go
+++ b/routers/repo/wiki.go
@@ -341,6 +341,11 @@ func NewWikiPost(ctx *context.Context, form auth.NewWikiForm) {
 		return
 	}
 
+	if util.IsEmptyString(form.Title) {
+		ctx.RenderWithErr(ctx.Tr("repo.issues.new.title_empty"), tplWikiNew, form)
+		return
+	}
+
 	wikiName := models.NormalizeWikiName(form.Title)
 	if err := ctx.Repo.Repository.AddWikiPage(ctx.User, wikiName, form.Content, form.Message); err != nil {
 		if models.IsErrWikiReservedName(err) {