blame,cat-file --textconv: Don't assume mode is ``S_IFREF | 0664''

We need to get the correct mode when blame reads the source from the
working tree, the index, or trees.  This allows us to omit running
textconv filters on symbolic links.

Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru>
Reviewed-by: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 23 insertions, 12 deletions

diff --git a/builtin/blame.c b/builtin/blame.c
index 28e3be2ea..173f286b1 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -83,6 +83,7 @@ struct origin {
 	struct commit *commit;
 	mmfile_t file;
 	unsigned char blob_sha1[20];
+	unsigned mode;
 	char path[FLEX_ARRAY];
 };
 
@@ -92,6 +93,7 @@ struct origin {
  * Return 1 if the conversion succeeds, 0 otherwise.
  */
 int textconv_object(const char *path,
+		    unsigned mode,
 		    const unsigned char *sha1,
 		    char **buf,
 		    unsigned long *buf_size)
@@ -100,7 +102,7 @@ int textconv_object(const char *path,
 	struct userdiff_driver *textconv;
 
 	df = alloc_filespec(path);
-	fill_filespec(df, sha1, S_IFREG | 0664);
+	fill_filespec(df, sha1, mode);
 	textconv = get_textconv(df);
 	if (!textconv) {
 		free_filespec(df);
@@ -125,7 +127,7 @@ static void fill_origin_blob(struct diff_options *opt,
 
 		num_read_blob++;
 		if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
-		    textconv_object(o->path, o->blob_sha1, &file->ptr, &file_size))
+		    textconv_object(o->path, o->mode, o->blob_sha1, &file->ptr, &file_size))
 			;
 		else
 			file->ptr = read_sha1_file(o->blob_sha1, &type, &file_size);
@@ -313,21 +315,23 @@ static struct origin *get_origin(struct scoreboard *sb,
  * for an origin is also used to pass the blame for the entire file to
  * the parent to detect the case where a child's blob is identical to
  * that of its parent's.
+ *
+ * This also fills origin->mode for corresponding tree path.
  */
-static int fill_blob_sha1(struct origin *origin)
+static int fill_blob_sha1_and_mode(struct origin *origin)
 {
-	unsigned mode;
 	if (!is_null_sha1(origin->blob_sha1))
 		return 0;
 	if (get_tree_entry(origin->commit->object.sha1,
 			   origin->path,
-			   origin->blob_sha1, &mode))
+			   origin->blob_sha1, &origin->mode))
 		goto error_out;
 	if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
 		goto error_out;
 	return 0;
  error_out:
 	hashclr(origin->blob_sha1);
+	origin->mode = S_IFINVALID;
 	return -1;
 }
 
@@ -360,12 +364,14 @@ static struct origin *find_origin(struct scoreboard *sb,
 			/*
 			 * If the origin was newly created (i.e. get_origin
 			 * would call make_origin if none is found in the
-			 * scoreboard), it does not know the blob_sha1,
+			 * scoreboard), it does not know the blob_sha1/mode,
 			 * so copy it.  Otherwise porigin was in the
-			 * scoreboard and already knows blob_sha1.
+			 * scoreboard and already knows blob_sha1/mode.
 			 */
-			if (porigin->refcnt == 1)
+			if (porigin->refcnt == 1) {
 				hashcpy(porigin->blob_sha1, cached->blob_sha1);
+				porigin->mode = cached->mode;
+			}
 			return porigin;
 		}
 		/* otherwise it was not very useful; free it */
@@ -400,6 +406,7 @@ static struct origin *find_origin(struct scoreboard *sb,
 		/* The path is the same as parent */
 		porigin = get_origin(sb, parent, origin->path);
 		hashcpy(porigin->blob_sha1, origin->blob_sha1);
+		porigin->mode = origin->mode;
 	} else {
 		/*
 		 * Since origin->path is a pathspec, if the parent
@@ -425,6 +432,7 @@ static struct origin *find_origin(struct scoreboard *sb,
 		case 'M':
 			porigin = get_origin(sb, parent, origin->path);
 			hashcpy(porigin->blob_sha1, p->one->sha1);
+			porigin->mode = p->one->mode;
 			break;
 		case 'A':
 		case 'T':
@@ -444,6 +452,7 @@ static struct origin *find_origin(struct scoreboard *sb,
 
 		cached = make_origin(porigin->commit, porigin->path);
 		hashcpy(cached->blob_sha1, porigin->blob_sha1);
+		cached->mode = porigin->mode;
 		parent->util = cached;
 	}
 	return porigin;
@@ -486,6 +495,7 @@ static struct origin *find_rename(struct scoreboard *sb,
 		    !strcmp(p->two->path, origin->path)) {
 			porigin = get_origin(sb, parent, p->one->path);
 			hashcpy(porigin->blob_sha1, p->one->sha1);
+			porigin->mode = p->one->mode;
 			break;
 		}
 	}
@@ -1099,6 +1109,7 @@ static int find_copy_in_parent(struct scoreboard *sb,
 
 			norigin = get_origin(sb, parent, p->one->path);
 			hashcpy(norigin->blob_sha1, p->one->sha1);
+			norigin->mode = p->one->mode;
 			fill_origin_blob(&sb->revs->diffopt, norigin, &file_p);
 			if (!file_p.ptr)
 				continue;
@@ -2083,7 +2094,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 		switch (st.st_mode & S_IFMT) {
 		case S_IFREG:
 			if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
-			    textconv_object(read_from, null_sha1, &buf.buf, &buf_len))
+			    textconv_object(read_from, mode, null_sha1, &buf.buf, &buf_len))
 				buf.len = buf_len;
 			else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
 				die_errno("cannot open or read '%s'", read_from);
@@ -2463,11 +2474,11 @@ parse_done:
 	}
 	else {
 		o = get_origin(&sb, sb.final, path);
-		if (fill_blob_sha1(o))
+		if (fill_blob_sha1_and_mode(o))
 			die("no such path %s in %s", path, final_commit_name);
 
 		if (DIFF_OPT_TST(&sb.revs->diffopt, ALLOW_TEXTCONV) &&
-		    textconv_object(path, o->blob_sha1, (char **) &sb.final_buf,
+		    textconv_object(path, o->mode, o->blob_sha1, (char **) &sb.final_buf,
 				    &sb.final_buf_size))
 			;
 		else
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 76ec3fec9..94632dbdb 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -143,7 +143,7 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
 			die("git cat-file --textconv %s: <object> must be <sha1:path>",
 			    obj_name);
 
-		if (!textconv_object(obj_context.path, sha1, &buf, &size))
+		if (!textconv_object(obj_context.path, obj_context.mode, sha1, &buf, &size))
 			die("git cat-file --textconv: unable to run textconv on %s",
 			    obj_name);
 		break;