enhance(pull)!: add per-repository default squash merge commit message (#39816)

Adds a repository setting for the default squash merge commit message
body with GitHub's options `PR_BODY`, `COMMIT_MESSAGES` and `BLANK`,
also settable via `squash_merge_commit_message` in the API. The commit
title stays the pull request title.

1. Breaking: API squash merges without `merge_message_field` now get the
same default message as the web merge box instead of a title-only
commit, which affects clients sending only `Do` like Renovate. An empty
value keeps title-only.
2. Breaking: `[repository.pull-request] DEFAULT_SQUASH_MERGE_MESSAGE`
replaces `POPULATE_SQUASH_COMMENT_WITH_COMMIT_MESSAGES`, which still
works as a deprecated fallback. Repositories store the default when
created or next saved.
3. Deprecated app.ini keys now migrate through one table instead of
per-loader fallbacks, which also fixes the ignored `[mailer] CERT_FILE`
and `KEY_FILE` fallbacks. Deprecation warnings no longer claim a removal
version.

<img width="1891" height="571" alt="grafik"
src="https://github.com/user-attachments/assets/0fdcde13-1f11-4156-b598-d80eb0d04cbe"
/>

---------

Co-authored-by: silverwind <me@silverwind.io>

tests/integration/api_pull_test.go

@@ -283,6 +283,17 @@ func TestAPIMergePull(t *testing.T) {
 			performMerge(t, prDTO.Index, map[string]any{"do": "merge", "delete_branch_after_merge": true})
 			checkBranchExists(t, newBranch, http.StatusNotFound)
 		})
+
+		t.Run("SquashMergePreservesFormMessage", func(t *testing.T) {
+			req := NewRequestWithValues(t, http.MethodPost, fmt.Sprintf("/api/v1/repos/%s/%s/pulls/%d/merge", owner.Name, repo.Name, createTestBranchPR(t, "squash-form-message").Index), map[string]string{
+				"do":                  "squash",
+				"merge_message_field": "custom squash message",
+			}).AddTokenAuth(apiCtx.Token)
+			MakeRequest(t, req, http.StatusOK)
+
+			req = NewRequestf(t, http.MethodGet, "/api/v1/repos/%s/%s/git/commits/%s", owner.Name, repo.Name, repo.DefaultBranch).AddTokenAuth(apiCtx.Token)
+			assert.Contains(t, DecodeJSON(t, MakeRequest(t, req, http.StatusOK), &api.Commit{}).RepoCommit.Message, "\n\ncustom squash message")
+		})
 	})
 }
 

tests/integration/api_repo_edit_test.go

@@ -506,7 +506,7 @@ func TestAPIRepoEdit(t *testing.T) {
 	})
 }
 
-func TestAPIRepoEditPullUpdateSettingsValidation(t *testing.T) {
+func TestAPIRepoEditPullSettings(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
 	user2 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
@@ -532,4 +532,14 @@ func TestAPIRepoEditPullUpdateSettingsValidation(t *testing.T) {
 		DefaultUpdateStyle: &defaultUpdateStyle,
 	}).AddTokenAuth(token)
 	MakeRequest(t, req, http.StatusBadRequest)
+
+	req = NewRequestWithJSON(t, "PATCH", repoURL, &api.EditRepoOption{
+		SquashMergeCommitMessage: new("invalid"),
+	}).AddTokenAuth(token)
+	MakeRequest(t, req, http.StatusBadRequest)
+
+	req = NewRequestWithJSON(t, "PATCH", repoURL, &api.EditRepoOption{
+		SquashMergeCommitMessage: new(string(repo_model.SquashMergeMessageBlank)),
+	}).AddTokenAuth(token)
+	assert.Equal(t, string(repo_model.SquashMergeMessageBlank), DecodeJSON(t, MakeRequest(t, req, http.StatusOK), &api.Repository{}).SquashMergeCommitMessage)
 }

tests/integration/pull_merge_test.go

@@ -24,6 +24,7 @@ import (
 	"gitea.dev/models/perm"
 	pull_model "gitea.dev/models/pull"
 	repo_model "gitea.dev/models/repo"
+	unit_model "gitea.dev/models/unit"
 	"gitea.dev/models/unittest"
 	user_model "gitea.dev/models/user"
 	"gitea.dev/models/webhook"
@@ -1214,7 +1215,7 @@ func TestPullSquashMessage(t *testing.T) {
 		user2 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
 		user2Session := loginUser(t, user2.Name)
 
-		defer test.MockVariableValue(&setting.Repository.PullRequest.PopulateSquashCommentWithCommitMessages, true)()
+		defer test.MockVariableValue(&setting.Repository.PullRequest.DefaultSquashMergeMessage, "COMMIT_MESSAGES")()
 		defer test.MockVariableValue(&setting.Repository.PullRequest.DefaultMergeMessageSize, 80)()
 
 		repo, err := repo_service.CreateRepository(t.Context(), user2, user2, repo_service.CreateRepoOptions{
@@ -1344,5 +1345,40 @@ Co-authored-by: user4 <user4@example.com>
 				assert.Equal(t, tc.expectedMessage, squashMergeCommitMessage)
 			})
 		}
+
+		t.Run("Repository default squash merge message", func(t *testing.T) {
+			pullRequest := unittest.AssertExistsAndLoadBean(t, &issues_model.PullRequest{BaseRepoID: repo.ID, Index: 1})
+			require.NoError(t, pullRequest.LoadIssue(t.Context()))
+			pullRequest.Issue.Content = "PR description"
+			pullRequest.BaseRepo = repo
+
+			prUnit, err := repo.GetUnit(t.Context(), unit_model.TypePullRequests)
+			require.NoError(t, err)
+			for style, expected := range map[repo_model.SquashMergeMessage]string{
+				repo_model.SquashMergeMessageBlank:  "",
+				repo_model.SquashMergeMessagePRBody: "PR description",
+			} {
+				prUnit.PullRequestsConfig().DefaultSquashMergeMessage = style
+				msg, err := pull_service.GetSquashMergeCommitMessages(t.Context(), pullRequest)
+				require.NoError(t, err)
+				assert.Equal(t, expected, msg, style)
+			}
+		})
+
+		t.Run("API squash merge without message uses repository default", func(t *testing.T) {
+			defer test.MockVariableValue(&setting.Repository.PullRequest.DefaultSquashMergeMessage, "PR_BODY")()
+			token := getTokenForLoggedInUser(t, user2Session, auth_model.AccessTokenScopeWriteRepository)
+			req := NewRequestWithJSON(t, "POST", fmt.Sprintf("/api/v1/repos/%s/%s/pulls/1/merge", user2.Name, repo.Name), map[string]string{"do": "squash"}).AddTokenAuth(token)
+			MakeRequest(t, req, http.StatusOK)
+
+			pullRequest := unittest.AssertExistsAndLoadBean(t, &issues_model.PullRequest{BaseRepoID: repo.ID, Index: 1})
+			gitRepo, err := git.OpenRepository(t.Context(), repo)
+			require.NoError(t, err)
+			defer gitRepo.Close()
+			commit, err := gitRepo.GetCommit(t.Context(), pullRequest.MergedCommitID)
+			require.NoError(t, err)
+			assert.Contains(t, commit.CommitMessage.MessageRaw, "Pull for test-branch-0 (#1)\n\n* commit msg 1\n\n* commit msg 2\n")
+			assert.Contains(t, commit.CommitMessage.MessageRaw, "\nReviewed-on: ")
+		})
 	})
 }