[PATCH] Simplify "reverse-diff" logic in the diff core.

Instead of swapping the arguments just before output, this patch
makes the swapping happen on the input side of the diff core,
when "reverse-diff" is in effect.  This greatly simplifies the
logic, but more importantly it is necessary for upcoming "copy
detection" work.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/diff.c b/diff.c
index c4b6b76..eae2fc3 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -350,15 +350,6 @@ static void run_external_diff(const char *name,
        int status;
        static int atexit_asked = 0;
 
-       if (reverse_diff) {
-               struct diff_spec *tmp_spec;
-               tmp_spec = one; one = two; two = tmp_spec;
-               if (other) {
-                       const char *tmp;
-                       tmp = name; name = other; other = tmp;
-               }
-       }
-
        if (!matches_pathspec(name) && (!other || !matches_pathspec(other)))
                return;
 
@@ -765,11 +756,12 @@ void diff_addremove(int addremove, unsigned mode,
        char concatpath[PATH_MAX];
        struct diff_spec spec[2], *one, *two;
 
+       if (reverse_diff)
+               addremove = (addremove == '+' ? '-' : '+');
+
        if (0 <= diff_raw_output) {
                if (!path)
                        path = "";
-               if (reverse_diff)
-                       addremove = (addremove == '+' ? '-' : '+');
                printf("%c%06o %s %s %s%s%c",
                       addremove,
                       mode,
@@ -806,24 +798,24 @@ void diff_change(unsigned old_mode, unsigned new_mode,
        char concatpath[PATH_MAX];
        struct diff_spec spec[2];
 
+       if (reverse_diff) {
+               unsigned tmp;
+               const unsigned char *tmp_c;
+               tmp = old_mode; old_mode = new_mode; new_mode = tmp;
+               tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
+       }
+
        if (0 <= diff_raw_output) {
                char old_hex[41];
                strcpy(old_hex, sha1_to_hex(old_sha1));
 
                if (!path)
                        path = "";
-               if (reverse_diff)
-                       printf("*%06o->%06o %s %s->%s %s%s%c",
-                              new_mode, old_mode,
-                              git_object_type(new_mode),
-                              sha1_to_hex(new_sha1), old_hex,
-                              base, path, diff_raw_output);
-               else
-                       printf("*%06o->%06o %s %s->%s %s%s%c",
-                              old_mode, new_mode,
-                              git_object_type(new_mode),
-                              old_hex, sha1_to_hex(new_sha1),
-                              base, path, diff_raw_output);
+               printf("*%06o->%06o %s %s->%s %s%s%c",
+                      old_mode, new_mode,
+                      git_object_type(new_mode),
+                      old_hex, sha1_to_hex(new_sha1),
+                      base, path, diff_raw_output);
                return;
        }
        if (S_ISDIR(new_mode))