Some improvements

routers/api/v1/repo/compare.go

@@ -11,6 +11,7 @@ import (
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unit"
 	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/gitrepo"
 	"code.gitea.io/gitea/modules/log"
 	api "code.gitea.io/gitea/modules/structs"
@@ -69,6 +70,8 @@ func CompareDiff(ctx *context.APIContext) {
 			ctx.NotFound("GetRepositoryByOwnerAndName")
 		case errors.Is(err, util.ErrInvalidArgument):
 			ctx.NotFound("ParseComparePathParams")
+		case git.IsErrNotExist(err):
+			ctx.NotFound("ParseComparePathParams")
 		default:
 			ctx.ServerError("GetRepositoryByOwnerAndName", err)
 		}

routers/api/v1/repo/pull.go

@@ -417,6 +417,8 @@ func CreatePullRequest(ctx *context.APIContext) {
 			ctx.NotFound("GetRepositoryByOwnerAndName")
 		case errors.Is(err, util.ErrInvalidArgument):
 			ctx.NotFound("ParseComparePathParams")
+		case git.IsErrNotExist(err):
+			ctx.NotFound("ParseComparePathParams")
 		default:
 			ctx.ServerError("GetRepositoryByOwnerAndName", err)
 		}

routers/common/compare.go

@@ -30,6 +30,10 @@ func (cr *CompareRouter) DirectComparison() bool {
 	return cr.DotTimes == 2
 }
 
+func (cr *CompareRouter) CompareDots() string {
+	return strings.Repeat(".", cr.DotTimes)
+}
+
 func parseBase(base string) (string, int) {
 	parts := strings.SplitN(base, "^", 2)
 	if len(parts) == 1 {

routers/common/compare_test.go

@@ -414,6 +414,26 @@ func Test_ParseComparePathParams(t *testing.T) {
 				IsHeadCommit: true,
 			},
 		},
+		{
+			repoName: "repo1",
+			hasClose: true,
+			router:   "user12/repo10:master",
+			compareInfo: &CompareInfo{
+				CompareRouter: &CompareRouter{
+					BaseOriRef:    repo11.DefaultBranch,
+					BaseFullRef:   git.RefNameFromBranch(repo11.DefaultBranch),
+					HeadOwnerName: "user12",
+					HeadRepoName:  "repo10",
+					HeadOriRef:    "master",
+					HeadFullRef:   git.RefNameFromBranch("master"),
+					DotTimes:      3,
+				},
+				BaseRepo:    repo1,
+				HeadUser:    repo10.Owner,
+				HeadRepo:    repo10,
+				HeadGitRepo: gitRepo10,
+			},
+		},
 	}
 
 	for _, kase := range kases {

routers/web/repo/compare.go

@@ -554,11 +554,8 @@ func CompareDiff(ctx *context.Context) {
 	}
 	beforeCommitID := ctx.Data["BeforeCommitID"].(string)
 	afterCommitID := ctx.Data["AfterCommitID"].(string)
+	separator := ci.CompareDots()
 
-	separator := "..."
-	if ci.DirectComparison() {
-		separator = ".."
-	}
 	ctx.Data["Title"] = "Comparing " + base.ShortSha(beforeCommitID) + separator + base.ShortSha(afterCommitID)
 
 	ctx.Data["IsDiffCompare"] = true