[GITEA] pulls: "Edit File" button in "Files Changed" tab

Closes #1894.
Gitea issue: https://github.com/go-gitea/gitea/issues/23848

(cherry picked from commit 79c75164ca70937261b1d9a68420ebfdbdcfa4d4)
(cherry picked from commit 58c76aad8f624d7701e3fa6c12264328962cdf58)
(cherry picked from commit 5bdb3c6c53527da23ba76a8289ca6a81c6fcecdf)
(cherry picked from commit 94e954ce2248f14082f0c3071cc076c118c4a791)
(cherry picked from commit 1388e7c7bef7a34018b993c24b34e053849eb93a)
(cherry picked from commit 6a234abff532bfc8806e0cccf8c2d1d8c3e90c24)

routers/web/repo/pull.go

@@ -967,6 +967,18 @@ func viewPullFiles(ctx *context.Context, specifiedStartCommit, specifiedEndCommi
 		return
 	}
 
+	// determine if the user viewing the pull request can edit the head branch
+	if ctx.Doer != nil && pull.HeadRepo != nil && !pull.HasMerged {
+		headRepoPerm, err := access_model.GetUserRepoPermission(ctx, pull.HeadRepo, ctx.Doer)
+		if err != nil {
+			ctx.ServerError("GetUserRepoPermission", err)
+			return
+		}
+		ctx.Data["HeadBranchIsEditable"] = pull.HeadRepo.CanEnableEditor() && issues_model.CanMaintainerWriteToBranch(ctx, headRepoPerm, pull.HeadBranch, ctx.Doer)
+		ctx.Data["SourceRepoLink"] = pull.HeadRepo.Link()
+		ctx.Data["HeadBranch"] = pull.HeadBranch
+	}
+
 	if ctx.IsSigned && ctx.Doer != nil {
 		if ctx.Data["CanMarkConversation"], err = issues_model.CanMarkConversation(ctx, issue, ctx.Doer); err != nil {
 			ctx.ServerError("CanMarkConversation", err)

templates/repo/diff/box.tmpl

@@ -166,6 +166,9 @@
 										<a class="ui basic tiny button" rel="nofollow" href="{{$.BeforeSourcePath}}/{{PathEscapeSegments .Name}}">{{ctx.Locale.Tr "repo.diff.view_file"}}</a>
 									{{else}}
 										<a class="ui basic tiny button" rel="nofollow" href="{{$.SourcePath}}/{{PathEscapeSegments .Name}}">{{ctx.Locale.Tr "repo.diff.view_file"}}</a>
+										{{if and $.HeadBranchIsEditable (not $file.IsLFSFile)}}
+											<a class="ui basic tiny button" rel="nofollow" href="{{$.SourceRepoLink}}/_edit/{{PathEscapeSegments $.HeadBranch}}/{{PathEscapeSegments .Name}}">{{ctx.Locale.Tr "repo.editor.edit_this_file"}}</a>
+										{{end}}
 									{{end}}
 								{{end}}
 								{{if $isReviewFile}}

tests/integration/forgejo_git_test.go

@@ -134,6 +134,6 @@ func doActionsUserPR(ctx, doerCtx APITestContext, baseBranch, headBranch string)
 		doerCtx.ExpectedCode = http.StatusCreated
 		t.Run("AutoMergePR", doAPIAutoMergePullRequest(doerCtx, ctx.Username, ctx.Reponame, pr.Index))
 		// Ensure the PR page works
-		t.Run("EnsureCanSeePull", doEnsureCanSeePull(ctx, pr))
+		t.Run("EnsureCanSeePull", doEnsureCanSeePull(ctx, pr, true))
 	}
 }

tests/integration/git_test.go

@@ -455,8 +455,19 @@ func doMergeFork(ctx, baseCtx APITestContext, baseBranch, headBranch string) fun
 			assert.NoError(t, err)
 		})
 
-		// Ensure the PR page works
+		// Ensure the PR page works.
-		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr))
+		// For the base repository owner, the PR is not editable (maintainer edits are not enabled):
+		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr, false))
+		// For the head repository owner, the PR is editable:
+		headSession := loginUser(t, "user2")
+		headToken := getTokenForLoggedInUser(t, headSession, auth_model.AccessTokenScopeReadRepository, auth_model.AccessTokenScopeReadUser)
+		headCtx := APITestContext{
+			Session:  headSession,
+			Token:    headToken,
+			Username: baseCtx.Username,
+			Reponame: baseCtx.Reponame,
+		}
+		t.Run("EnsureCanSeePull", doEnsureCanSeePull(headCtx, pr, true))
 
 		// Then get the diff string
 		var diffHash string
@@ -470,7 +481,9 @@ func doMergeFork(ctx, baseCtx APITestContext, baseBranch, headBranch string) fun
 
 		// Now: Merge the PR & make sure that doesn't break the PR page or change its diff
 		t.Run("MergePR", doAPIMergePullRequest(baseCtx, baseCtx.Username, baseCtx.Reponame, pr.Index))
-		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr))
+		// for both users the PR is still visible but not editable anymore after it was merged
+		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr, false))
+		t.Run("EnsureCanSeePull", doEnsureCanSeePull(headCtx, pr, false))
 		t.Run("CheckPR", func(t *testing.T) {
 			oldMergeBase := pr.MergeBase
 			pr2, err := doAPIGetPullRequest(baseCtx, baseCtx.Username, baseCtx.Reponame, pr.Index)(t)
@@ -481,12 +494,12 @@ func doMergeFork(ctx, baseCtx APITestContext, baseBranch, headBranch string) fun
 
 		// Then: Delete the head branch & make sure that doesn't break the PR page or change its diff
 		t.Run("DeleteHeadBranch", doBranchDelete(baseCtx, baseCtx.Username, baseCtx.Reponame, headBranch))
-		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr))
+		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr, false))
 		t.Run("EnsureDiffNoChange", doEnsureDiffNoChange(baseCtx, pr, diffHash, diffLength))
 
 		// Delete the head repository & make sure that doesn't break the PR page or change its diff
 		t.Run("DeleteHeadRepository", doAPIDeleteRepository(ctx))
-		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr))
+		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr, false))
 		t.Run("EnsureDiffNoChange", doEnsureDiffNoChange(baseCtx, pr, diffHash, diffLength))
 	}
 }
@@ -520,12 +533,19 @@ func doCreatePRAndSetManuallyMerged(ctx, baseCtx APITestContext, dstPath, baseBr
 	}
 }
 
-func doEnsureCanSeePull(ctx APITestContext, pr api.PullRequest) func(t *testing.T) {
+func doEnsureCanSeePull(ctx APITestContext, pr api.PullRequest, editable bool) func(t *testing.T) {
 	return func(t *testing.T) {
 		req := NewRequest(t, "GET", fmt.Sprintf("/%s/%s/pulls/%d", url.PathEscape(ctx.Username), url.PathEscape(ctx.Reponame), pr.Index))
 		ctx.Session.MakeRequest(t, req, http.StatusOK)
 		req = NewRequest(t, "GET", fmt.Sprintf("/%s/%s/pulls/%d/files", url.PathEscape(ctx.Username), url.PathEscape(ctx.Reponame), pr.Index))
-		ctx.Session.MakeRequest(t, req, http.StatusOK)
+		resp := ctx.Session.MakeRequest(t, req, http.StatusOK)
+		doc := NewHTMLParser(t, resp.Body)
+		editButtonCount := doc.doc.Find("div.diff-file-header-actions a[href*='/_edit/']").Length()
+		if editable {
+			assert.Greater(t, editButtonCount, 0, "Expected to find a button to edit a file in the PR diff view but there were none")
+		} else {
+			assert.Equal(t, 0, editButtonCount, "Expected not to find any buttons to edit files in PR diff view but there were some")
+		}
 		req = NewRequest(t, "GET", fmt.Sprintf("/%s/%s/pulls/%d/commits", url.PathEscape(ctx.Username), url.PathEscape(ctx.Reponame), pr.Index))
 		ctx.Session.MakeRequest(t, req, http.StatusOK)
 	}