patch-ids: add flag to create the diff patch id using header only data

diff --git a/diff.c b/diff.c
index fa78fc189cd7225767817a2d24ef6c3b19bef9d8..bb816d9cba6a8b46130251570fa425ff423f2ea1 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -4449,7 +4449,7 @@ static void patch_id_consume(void *priv, char *line, unsigned long len)
 }
 
 /* returns 0 upon success, and writes result into sha1 */
-static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
+static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
@@ -4484,9 +4484,6 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
 
                diff_fill_sha1_info(p->one);
                diff_fill_sha1_info(p->two);
-               if (fill_mmfile(&mf1, p->one) < 0 ||
-                               fill_mmfile(&mf2, p->two) < 0)
-                       return error("unable to read files to diff");
 
                len1 = remove_space(p->one->path, strlen(p->one->path));
                len2 = remove_space(p->two->path, strlen(p->two->path));
@@ -4521,6 +4518,13 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
                                        len2, p->two->path);
                git_SHA1_Update(&ctx, buffer, len1);
 
+               if (diff_header_only)
+                       continue;
+
+               if (fill_mmfile(&mf1, p->one) < 0 ||
+                   fill_mmfile(&mf2, p->two) < 0)
+                       return error("unable to read files to diff");
+
                if (diff_filespec_is_binary(p->one) ||
                    diff_filespec_is_binary(p->two)) {
                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
@@ -4541,11 +4545,11 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
        return 0;
 }
 
-int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
+int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
-       int result = diff_get_patch_id(options, sha1);
+       int result = diff_get_patch_id(options, sha1, diff_header_only);
 
        for (i = 0; i < q->nr; i++)
                diff_free_filepair(q->queue[i]);