Show fixup base commits in correct order in ctrl-f error message

pkg/commands/git_commands/commit.go

@@ -217,20 +217,6 @@ func (self *CommitCommands) GetCommitMessagesFirstLine(hashes []string) (string,
 	return self.cmd.New(cmdArgs).DontLog().RunWithOutput()
 }
 
-// Example output:
-//
-//	cd50c79ae Preserve the commit message correctly even if the description has blank lines
-//	3ebba5f32 Add test demonstrating a bug with preserving the commit message
-//	9a423c388 Remove unused function
-func (self *CommitCommands) GetHashesAndCommitMessagesFirstLine(hashes []string) (string, error) {
-	cmdArgs := NewGitCmd("show").
-		Arg("--no-patch", "--pretty=format:%h %s").
-		Arg(hashes...).
-		ToArgv()
-
-	return self.cmd.New(cmdArgs).DontLog().RunWithOutput()
-}
-
 func (self *CommitCommands) GetCommitsOneline(hashes []string) (string, error) {
 	cmdArgs := NewGitCmd("show").
 		Arg("--no-patch", "--oneline").

pkg/gui/controllers/helpers/fixup_helper.go

@@ -114,10 +114,7 @@ func (self *FixupHelper) HandleFindBaseCommitForFixupPress() error {
 		// If there are multiple commits that could be the base commit, list
 		// them in the error message. But only the candidates from the current
 		// branch, not including any that are already merged.
-		subjects, err := self.c.Git().Commit.GetHashesAndCommitMessagesFirstLine(hashGroups[NOT_MERGED])
-		if err != nil {
-			return err
-		}
+		subjects := self.getHashesAndSubjects(commits, hashGroups[NOT_MERGED])
 		message := lo.Ternary(hasStagedChanges,
 			self.c.Tr.MultipleBaseCommitsFoundStaged,
 			self.c.Tr.MultipleBaseCommitsFoundUnstaged)
@@ -146,6 +143,23 @@ func (self *FixupHelper) HandleFindBaseCommitForFixupPress() error {
 	})
 }
 
+func (self *FixupHelper) getHashesAndSubjects(commits []*models.Commit, hashes []string) string {
+	// This is called only for the NOT_MERGED commits, and we know that all of them are contained in
+	// the commits slice.
+	commitsSet := set.NewFromSlice(hashes)
+	subjects := make([]string, 0, len(hashes))
+	for _, c := range commits {
+		if commitsSet.Includes(c.Hash()) {
+			subjects = append(subjects, fmt.Sprintf("%s %s", c.ShortRefName(), c.Name))
+			commitsSet.Remove(c.Hash())
+			if commitsSet.Len() == 0 {
+				break
+			}
+		}
+	}
+	return strings.Join(subjects, "\n")
+}
+
 func (self *FixupHelper) getDiff() (string, bool, error) {
 	args := []string{"-U0", "--ignore-submodules=all", "HEAD", "--"}
 

pkg/integration/tests/commit/find_base_commit_for_fixup.go

@@ -36,9 +36,9 @@ var FindBaseCommitForFixup = NewIntegrationTest(NewIntegrationTestArgs{
 		t.ExpectPopup().Alert().
 			Title(Equals("Error")).
 			Content(
-				Contains("Multiple base commits found").
-					Contains("2nd commit").
-					Contains("3rd commit"),
+				MatchesRegexp("Multiple base commits found.*\n\n" +
+					".*3rd commit\n" +
+					".*2nd commit"),
 			).
 			Confirm()
 

pkg/integration/tests/commit/find_base_commit_for_fixup_only_added_lines.go

@@ -39,9 +39,11 @@ var FindBaseCommitForFixupOnlyAddedLines = NewIntegrationTest(NewIntegrationTest
 		t.ExpectPopup().Alert().
 			Title(Equals("Error")).
 			Content(
-				Contains("Multiple base commits found").
-					Contains("3rd commit").
-					Contains("4th commit"),
+				MatchesRegexp(
+					"Multiple base commits found.*\n\n" +
+						".*4th commit\n" +
+						".*3rd commit",
+				),
 			).
 			Confirm()