merge-recursive: make "Auto-merging" comment show for other merges

Previously, merge_content() would print "Auto-merging" whenever the final
content and mode aren't already available from HEAD.  There are a few
problems with this:

  1) There are other code paths doing merges that should probably have the
     same message printed, in particular rename/rename(2to1) which cannot
     call into the normal rename logic.

  2) If both sides of the merge have modifications, then a content merge
     is needed.  It may turn out that the end result matches one of the
     sides (because the other only had a subset of the same changes), but
     the merge was still needed.  Currently, the message will not print in
     that case, though it seems like it should.

Move the printing of this message to merge_file_1() in order to address
both issues.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

merge-recursive.c

@@ -1063,12 +1063,13 @@ static int merge_3way(struct merge_options *o,
 }
 
 static int merge_file_1(struct merge_options *o,
-					   const struct diff_filespec *one,
-					   const struct diff_filespec *a,
-					   const struct diff_filespec *b,
-					   const char *branch1,
-					   const char *branch2,
-					   struct merge_file_info *result)
+			const struct diff_filespec *one,
+			const struct diff_filespec *a,
+			const struct diff_filespec *b,
+			const char *filename,
+			const char *branch1,
+			const char *branch2,
+			struct merge_file_info *result)
 {
 	result->merge = 0;
 	result->clean = 1;
@@ -1148,18 +1149,22 @@ static int merge_file_1(struct merge_options *o,
 			die("BUG: unsupported object type in the tree");
 	}
 
+	if (result->merge)
+		output(o, 2, _("Auto-merging %s"), filename);
+
 	return 0;
 }
 
 static int merge_file_special_markers(struct merge_options *o,
-			   const struct diff_filespec *one,
-			   const struct diff_filespec *a,
-			   const struct diff_filespec *b,
-			   const char *branch1,
-			   const char *filename1,
-			   const char *branch2,
-			   const char *filename2,
-			   struct merge_file_info *mfi)
+				      const struct diff_filespec *one,
+				      const struct diff_filespec *a,
+				      const struct diff_filespec *b,
+				      const char *target_filename,
+				      const char *branch1,
+				      const char *filename1,
+				      const char *branch2,
+				      const char *filename2,
+				      struct merge_file_info *mfi)
 {
 	char *side1 = NULL;
 	char *side2 = NULL;
@@ -1170,22 +1175,23 @@ static int merge_file_special_markers(struct merge_options *o,
 	if (filename2)
 		side2 = xstrfmt("%s:%s", branch2, filename2);
 
-	ret = merge_file_1(o, one, a, b,
+	ret = merge_file_1(o, one, a, b, target_filename,
 			   side1 ? side1 : branch1,
 			   side2 ? side2 : branch2, mfi);
+
 	free(side1);
 	free(side2);
 	return ret;
 }
 
 static int merge_file_one(struct merge_options *o,
-					 const char *path,
-					 const struct object_id *o_oid, int o_mode,
-					 const struct object_id *a_oid, int a_mode,
-					 const struct object_id *b_oid, int b_mode,
-					 const char *branch1,
-					 const char *branch2,
-					 struct merge_file_info *mfi)
+			  const char *path,
+			  const struct object_id *o_oid, int o_mode,
+			  const struct object_id *a_oid, int a_mode,
+			  const struct object_id *b_oid, int b_mode,
+			  const char *branch1,
+			  const char *branch2,
+			  struct merge_file_info *mfi)
 {
 	struct diff_filespec one, a, b;
 
@@ -1196,7 +1202,7 @@ static int merge_file_one(struct merge_options *o,
 	a.mode = a_mode;
 	oidcpy(&b.oid, b_oid);
 	b.mode = b_mode;
-	return merge_file_1(o, &one, &a, &b, branch1, branch2, mfi);
+	return merge_file_1(o, &one, &a, &b, path, branch1, branch2, mfi);
 }
 
 static int conflict_rename_dir(struct merge_options *o,
@@ -1474,6 +1480,8 @@ static int conflict_rename_rename_2to1(struct merge_options *o,
 	struct diff_filespec *c1 = ci->pair1->two;
 	struct diff_filespec *c2 = ci->pair2->two;
 	char *path = c1->path; /* == c2->path */
+	char *path_side_1_desc;
+	char *path_side_2_desc;
 	struct merge_file_info mfi_c1;
 	struct merge_file_info mfi_c2;
 	int ret;
@@ -1487,13 +1495,19 @@ static int conflict_rename_rename_2to1(struct merge_options *o,
 	remove_file(o, 1, a->path, o->call_depth || would_lose_untracked(a->path));
 	remove_file(o, 1, b->path, o->call_depth || would_lose_untracked(b->path));
 
+	path_side_1_desc = xstrfmt("%s (was %s)", path, a->path);
+	path_side_2_desc = xstrfmt("%s (was %s)", path, b->path);
 	if (merge_file_special_markers(o, a, c1, &ci->ren1_other,
+				       path_side_1_desc,
 				       o->branch1, c1->path,
 				       o->branch2, ci->ren1_other.path, &mfi_c1) ||
 	    merge_file_special_markers(o, b, &ci->ren2_other, c2,
+				       path_side_2_desc,
 				       o->branch1, ci->ren2_other.path,
 				       o->branch2, c2->path, &mfi_c2))
 		return -1;
+	free(path_side_1_desc);
+	free(path_side_2_desc);
 
 	if (o->call_depth) {
 		/*
@@ -2802,7 +2816,7 @@ static int merge_content(struct merge_options *o,
 			       S_ISGITLINK(pair1->two->mode)))
 			df_conflict_remains = 1;
 	}
-	if (merge_file_special_markers(o, &one, &a, &b,
+	if (merge_file_special_markers(o, &one, &a, &b, path,
 				       o->branch1, path1,
 				       o->branch2, path2, &mfi))
 		return -1;
@@ -2824,8 +2838,7 @@ static int merge_content(struct merge_options *o,
 				return -1;
 			return mfi.clean;
 		}
-	} else
-		output(o, 2, _("Auto-merging %s"), path);
+	}
 
 	if (!mfi.clean) {
 		if (S_ISGITLINK(mfi.mode))