apply: refactor read_file_or_gitlink()

diff --git a/builtin/apply.c b/builtin/apply.c
index 725712d7888c1a5503c2249c6dbd50ee796c2851..15bcbb0f2d392a1819ec587be83e2828a78ddb1f 100644 (file)
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -371,8 +371,8 @@ static void prepare_image(struct image *image, char *buf, size_t len,
 static void clear_image(struct image *image)
 {
        free(image->buf);
-       image->buf = NULL;
-       image->len = 0;
+       free(image->line_allocated);
+       memset(image, 0, sizeof(*image));
 }
 
 /* fmt must contain _one_ %s and no other substitution */
@@ -2930,20 +2930,17 @@ static int apply_fragments(struct image *img, struct patch *patch)
        return 0;
 }
 
-static int read_file_or_gitlink(struct cache_entry *ce, struct strbuf *buf)
+static int read_blob_object(struct strbuf *buf, const unsigned char *sha1, unsigned mode)
 {
-       if (!ce)
-               return 0;
-
-       if (S_ISGITLINK(ce->ce_mode)) {
+       if (S_ISGITLINK(mode)) {
                strbuf_grow(buf, 100);
-               strbuf_addf(buf, "Subproject commit %s\n", sha1_to_hex(ce->sha1));
+               strbuf_addf(buf, "Subproject commit %s\n", sha1_to_hex(sha1));
        } else {
                enum object_type type;
                unsigned long sz;
                char *result;
 
-               result = read_sha1_file(ce->sha1, &type, &sz);
+               result = read_sha1_file(sha1, &type, &sz);
                if (!result)
                        return -1;
                /* XXX read_sha1_file NUL-terminates */
@@ -2952,6 +2949,13 @@ static int read_file_or_gitlink(struct cache_entry *ce, struct strbuf *buf)
        return 0;
 }
 
+static int read_file_or_gitlink(struct cache_entry *ce, struct strbuf *buf)
+{
+       if (!ce)
+               return 0;
+       return read_blob_object(buf, ce->sha1, ce->ce_mode);
+}
+
 static struct patch *in_fn_table(const char *name)
 {
        struct string_list_item *item;
@@ -2970,9 +2974,15 @@ static struct patch *in_fn_table(const char *name)
  * item->util in the filename table records the status of the path.
  * Usually it points at a patch (whose result records the contents
  * of it after applying it), but it could be PATH_WAS_DELETED for a
- * path that a previously applied patch has already removed.
+ * path that a previously applied patch has already removed, or
+ * PATH_TO_BE_DELETED for a path that a later patch would remove.
+ *
+ * The latter is needed to deal with a case where two paths A and B
+ * are swapped by first renaming A to B and then renaming B to A;
+ * moving A to B should not be prevented due to presense of B as we
+ * will remove it in a later patch.
  */
- #define PATH_TO_BE_DELETED ((struct patch *) -2)
+#define PATH_TO_BE_DELETED ((struct patch *) -2)
 #define PATH_WAS_DELETED ((struct patch *) -1)
 
 static int to_be_deleted(struct patch *patch)
@@ -3218,16 +3228,22 @@ static int check_patch(struct patch *patch)
                return status;
        old_name = patch->old_name;
 
+       /*
+        * A type-change diff is always split into a patch to delete
+        * old, immediately followed by a patch to create new (see
+        * diff.c::run_diff()); in such a case it is Ok that the entry
+        * to be deleted by the previous patch is still in the working
+        * tree and in the index.
+        *
+        * A patch to swap-rename between A and B would first rename A
+        * to B and then rename B to A.  While applying the first one,
+        * the presense of B should not stop A from getting renamed to
+        * B; ask to_be_deleted() about the later rename.  Removal of
+        * B and rename from A to B is handled the same way by asking
+        * was_deleted().
+        */
        if ((tpatch = in_fn_table(new_name)) &&
-                       (was_deleted(tpatch) || to_be_deleted(tpatch)))
-               /*
-                * A type-change diff is always split into a patch to
-                * delete old, immediately followed by a patch to
-                * create new (see diff.c::run_diff()); in such a case
-                * it is Ok that the entry to be deleted by the
-                * previous patch is still in the working tree and in
-                * the index.
-                */
+           (was_deleted(tpatch) || to_be_deleted(tpatch)))
                ok_if_exists = 1;
        else
                ok_if_exists = 0;