cm24576-reimplement-listconflictfiles-with-git-merge-tree-1

2 files changed, 47 insertions, 16 deletions

diff --git a/internal/git/localrepo/merge.go b/internal/git/localrepo/merge.go
index f34aa52a6..d0b67cc7b 100644
--- a/internal/git/localrepo/merge.go
+++ b/internal/git/localrepo/merge.go
@@ -101,9 +101,7 @@ func (repo *Repo) MergeTree(
 
 		if exitCode > 1 {
 			if text.ChompBytes(stderr.Bytes()) == "fatal: refusing to merge unrelated histories" {
-				return "", &MergeTreeError{
-					InfoMessage: "unrelated histories",
-				}
+				return "", &MergeTreeError{}
 			}
 			return "", fmt.Errorf("merge-tree: %w", err)
 		}
@@ -141,8 +139,6 @@ func parseMergeTreeError(objectHash git.ObjectHash, cfg mergeTreeConfig, output
 		return "", fmt.Errorf("hex to oid: %w", err)
 	}
 
-	mergeTreeError.InfoMessage = strings.TrimSuffix(infoMsg, "\x00")
-
 	mergeTreeError.ConflictingFileInfo = make([]ConflictingFileInfo, len(oidAndConflicts[1:]))
 
 	// From git-merge-tree(1), the information is of the format `<mode> <object> <stage> <filename>`
@@ -181,6 +177,31 @@ func parseMergeTreeError(objectHash git.ObjectHash, cfg mergeTreeConfig, output
 		}
 	}
 
+	fields := strings.Split(infoMsg, "\x00")
+	// The git output contains a null characted at the end, which creates a stray empty field.
+	fields = fields[:len(fields)-1]
+
+	for i := 0; i < len(fields); {
+		c := ConflictInfoMessage{}
+
+		numOfPaths, err := strconv.Atoi(fields[i])
+		if err != nil {
+			return "", fmt.Errorf("converting stage to int: %w", err)
+		}
+
+		if i+numOfPaths+2 > len(fields) {
+			return "", fmt.Errorf("incorrect number of fields: %s", infoMsg)
+		}
+
+		c.Paths = fields[i+1 : i+numOfPaths+1]
+		c.Type = fields[i+numOfPaths+1]
+		c.Message = fields[i+numOfPaths+2]
+
+		mergeTreeError.ConflictInfoMessage = append(mergeTreeError.ConflictInfoMessage, c)
+
+		i = i + numOfPaths + 3
+	}
+
 	return oid, &mergeTreeError
 }
 
@@ -191,11 +212,17 @@ type ConflictingFileInfo struct {
 	Stage    MergeStage
 }
 
+type ConflictInfoMessage struct {
+	Paths   []string
+	Type    string
+	Message string
+}
+
 // MergeTreeError encapsulates any conflicting file info and messages that occur
 // when a merge-tree(1) command fails.
 type MergeTreeError struct {
 	ConflictingFileInfo []ConflictingFileInfo
-	InfoMessage         string
+	ConflictInfoMessage []ConflictInfoMessage
 }
 
 // Error returns the error string for a conflict error.
diff --git a/internal/git/localrepo/merge_test.go b/internal/git/localrepo/merge_test.go
index ede6456b8..3a8e78c42 100644
--- a/internal/git/localrepo/merge_test.go
+++ b/internal/git/localrepo/merge_test.go
@@ -95,10 +95,8 @@ func TestMergeTree(t *testing.T) {
 			},
 		},
 		{
-			desc: "no shared ancestors",
-			expectedErr: &MergeTreeError{
-				InfoMessage: "unrelated histories",
-			},
+			desc:        "no shared ancestors",
+			expectedErr: &MergeTreeError{},
 			setupFunc: func(t *testing.T, ctx context.Context, repoPath string) (git.ObjectID, git.ObjectID, []gittest.TreeEntry) {
 				tree1 := gittest.WriteTree(t, cfg, repoPath, []gittest.TreeEntry{
 					{
@@ -138,7 +136,6 @@ func TestMergeTree(t *testing.T) {
 						Stage:    0,
 					},
 				},
-				InfoMessage: "1\x00file2\x00Auto-merging\x00Auto-merging file2\n\x001\x00file2\x00CONFLICT (contents)\x00CONFLICT (add/add): Merge conflict in file2\n",
 			},
 			setupFunc: func(t *testing.T, ctx context.Context, repoPath string) (git.ObjectID, git.ObjectID, []gittest.TreeEntry) {
 				tree1 := gittest.WriteTree(t, cfg, repoPath, []gittest.TreeEntry{
@@ -321,7 +318,18 @@ func TestParseResult(t *testing.T) {
 						Stage:    MergeStageTheirs,
 					},
 				},
-				InfoMessage: "1\x00a\x00Auto-merging\x00Auto-merging a\n\x001\x00a\x00CONFLICT (contents)\x00CONFLICT (content): Merge conflict in a\n",
+				ConflictInfoMessage: []ConflictInfoMessage{
+					{
+						Paths:   []string{"a"},
+						Type:    "Auto-merging",
+						Message: "Auto-merging a\n",
+					},
+					{
+						Paths:   []string{"a"},
+						Type:    "CONFLICT (contents)",
+						Message: "CONFLICT (content): Merge conflict in a\n",
+					},
+				},
 			},
 		},
 		{
@@ -361,7 +369,6 @@ func TestParseResult(t *testing.T) {
 						Stage:    MergeStageTheirs,
 					},
 				},
-				InfoMessage: "1\x00a\x00Auto-merging\x00Auto-merging a\n\x001\x00a\x00CONFLICT (contents)\x00CONFLICT (content): Merge conflict in a\n",
 			},
 		},
 		{
@@ -399,7 +406,6 @@ func TestParseResult(t *testing.T) {
 						Stage:    MergeStageTheirs,
 					},
 				},
-				InfoMessage: "3\x00a\x00c\x00d\x00CONFLICT (rename/rename)\x00CONFLICT (rename/rename): a renamed to c in @ and to d in master.\n",
 			},
 		},
 		{
@@ -459,7 +465,6 @@ func TestParseResult(t *testing.T) {
 						Stage:    MergeStageTheirs,
 					},
 				},
-				InfoMessage: "1\x00a\x00Auto-merging\x00Auto-merging a\n\x001\x00a\x00CONFLICT (contents)\x00CONFLICT (content): Merge conflict in a\n\x001\x00b\x00Auto-merging\x00Auto-merging b\n\x001\x00b\x00CONFLICT (contents)\x00CONFLICT (content): Merge conflict in b\n",
 			},
 		},
 		{
@@ -509,7 +514,6 @@ func TestParseResult(t *testing.T) {
 						Stage:    MergeStageTheirs,
 					},
 				},
-				InfoMessage: "1\x00a\x00CONFLICT (modify/delete)\x00CONFLICT (modify/delete): a deleted in @ and modified in master.  Version master of a left in tree.\n\x001\x00b\x00Auto-merging\x00Auto-merging b\n\x001\x00b\x00CONFLICT (contents)\x00CONFLICT (content): Merge conflict in b\n",
 			},
 		},
 		{