Fix the bug described in the previous commit

What happens here is that when stopping on an "edit" todo entry, we rely on the
assumption that if the .git/rebase-merge/amend file exists, the command was
successful, and if it doesn't, there was a conflict. The problem is that when
you stop on an edit command, and then run a multi-commit cherry-pick or rebase,
this will delete the amend file. You may or may not consider this a bug in git;
to work around it, we also check the existence of the rebase-merge/message file,
which will be deleted as well by the cherry-pick or revert.

pkg/commands/git_commands/commit_loader.go

@@ -388,15 +388,13 @@ func (self *CommitLoader) getConflictedCommit(todos []todo.Todo) *models.Commit
 		return nil
 	}
 
-	amendFileExists := false
+	amendFileExists, _ := self.os.FileExists(filepath.Join(self.repoPaths.WorktreeGitDirPath(), "rebase-merge/amend"))
-	if _, err := os.Stat(filepath.Join(self.repoPaths.WorktreeGitDirPath(), "rebase-merge/amend")); err == nil {
+	messageFileExists, _ := self.os.FileExists(filepath.Join(self.repoPaths.WorktreeGitDirPath(), "rebase-merge/message"))
-		amendFileExists = true
-	}
 
-	return self.getConflictedCommitImpl(todos, doneTodos, amendFileExists)
+	return self.getConflictedCommitImpl(todos, doneTodos, amendFileExists, messageFileExists)
 }
 
-func (self *CommitLoader) getConflictedCommitImpl(todos []todo.Todo, doneTodos []todo.Todo, amendFileExists bool) *models.Commit {
+func (self *CommitLoader) getConflictedCommitImpl(todos []todo.Todo, doneTodos []todo.Todo, amendFileExists bool, messageFileExists bool) *models.Commit {
 	// Should never be possible, but just to be safe:
 	if len(doneTodos) == 0 {
 		self.Log.Error("no done entries in rebase-merge/done file")
@@ -449,6 +447,14 @@ func (self *CommitLoader) getConflictedCommitImpl(todos []todo.Todo, doneTodos [
 			// command was successful, otherwise it wasn't
 			return nil
 		}
+
+		if !messageFileExists {
+			// As an additional check, see if the "message" file exists; if it
+			// doesn't, it must be because a multi-commit cherry-pick or revert
+			// was performed in the meantime, which deleted both the amend file
+			// and the message file.
+			return nil
+		}
 	}
 
 	// I don't think this is ever possible, but again, just to be safe:

pkg/commands/git_commands/commit_loader_test.go

@@ -332,6 +332,7 @@ func TestCommitLoader_getConflictedCommitImpl(t *testing.T) {
 		todos             []todo.Todo
 		doneTodos         []todo.Todo
 		amendFileExists   bool
+		messageFileExists bool
 		expectedResult    *models.Commit
 	}{
 		{
@@ -475,7 +476,7 @@ func TestCommitLoader_getConflictedCommitImpl(t *testing.T) {
 			expectedResult:  nil,
 		},
 		{
-			testName: "'edit' without amend file",
+			testName: "'edit' without amend file but message file",
 			todos:    []todo.Todo{},
 			doneTodos: []todo.Todo{
 				{
@@ -484,12 +485,26 @@ func TestCommitLoader_getConflictedCommitImpl(t *testing.T) {
 				},
 			},
 			amendFileExists:   false,
+			messageFileExists: true,
 			expectedResult: &models.Commit{
 				Hash:   "fa1afe1",
 				Action: todo.Edit,
 				Status: models.StatusConflicted,
 			},
 		},
+		{
+			testName: "'edit' without amend and without message file",
+			todos:    []todo.Todo{},
+			doneTodos: []todo.Todo{
+				{
+					Command: todo.Edit,
+					Commit:  "fa1afe1",
+				},
+			},
+			amendFileExists:   false,
+			messageFileExists: false,
+			expectedResult:    nil,
+		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.testName, func(t *testing.T) {
@@ -508,7 +523,7 @@ func TestCommitLoader_getConflictedCommitImpl(t *testing.T) {
 				},
 			}
 
-			hash := builder.getConflictedCommitImpl(scenario.todos, scenario.doneTodos, scenario.amendFileExists)
+			hash := builder.getConflictedCommitImpl(scenario.todos, scenario.doneTodos, scenario.amendFileExists, scenario.messageFileExists)
 			assert.Equal(t, scenario.expectedResult, hash)
 		})
 	}

pkg/integration/tests/interactive_rebase/revert_during_rebase_when_stopped_on_edit.go

@@ -45,7 +45,6 @@ var RevertDuringRebaseWhenStoppedOnEdit = NewIntegrationTest(NewIntegrationTestA
 			).
 			Press("X").
 			Lines(
-				/* EXPECTED:
 				Contains("pick").Contains("commit 04"),
 				Contains(`<-- YOU ARE HERE --- Revert "commit 01"`).IsSelected(),
 				Contains(`Revert "commit 02"`),
@@ -53,15 +52,6 @@ var RevertDuringRebaseWhenStoppedOnEdit = NewIntegrationTest(NewIntegrationTestA
 				Contains("commit 02"),
 				Contains("commit 01"),
 				Contains("master commit"),
-				ACTUAL: */
-				Contains("pick").Contains("commit 04"),
-				Contains("edit").Contains("<-- CONFLICT --- commit 03").IsSelected(),
-				Contains(`Revert "commit 01"`),
-				Contains(`Revert "commit 02"`),
-				Contains("commit 03"),
-				Contains("commit 02"),
-				Contains("commit 01"),
-				Contains("master commit"),
 			)
 	},
 })

pkg/integration/tests/interactive_rebase/revert_multiple_commits_in_interactive_rebase.go

@@ -84,7 +84,6 @@ var RevertMultipleCommitsInInteractiveRebase = NewIntegrationTest(NewIntegration
 
 		t.Views().Commits().
 			Lines(
-				/* EXPECTED:
 				Contains("pick").Contains("CI unrelated change 3"),
 				Contains("pick").Contains("CI unrelated change 2"),
 				Contains(`CI ◯ <-- YOU ARE HERE --- Revert "unrelated change 1"`),
@@ -93,16 +92,6 @@ var RevertMultipleCommitsInInteractiveRebase = NewIntegrationTest(NewIntegration
 				Contains("CI ◯ add first line"),
 				Contains("CI ◯ unrelated change 1"),
 				Contains("CI ◯ add empty file"),
-				ACTUAL: */
-				Contains("pick").Contains("CI unrelated change 3"),
-				Contains("pick").Contains("CI unrelated change 2"),
-				Contains("edit  CI <-- CONFLICT --- add second line"),
-				Contains(`CI ◯ Revert "unrelated change 1"`),
-				Contains(`CI ◯ Revert "add first line"`),
-				Contains("CI ◯ add second line"),
-				Contains("CI ◯ add first line"),
-				Contains("CI ◯ unrelated change 1"),
-				Contains("CI ◯ add empty file"),
 			)
 
 		t.Views().Options().Content(Contains("View rebase options: m"))