Fix "git diff blob1 blob2" showing the diff in reverse.

diff --git a/builtin-diff.c b/builtin-diff.c
index cb38f445611735cff5bc9fbafb3189e6ccc6c2fd..ec27542d484b8a1d69d1ea5a57ba795f5a78b35c 100644 (file)
--- a/builtin-diff.c
+++ b/builtin-diff.c
@@ -125,9 +125,6 @@ static int builtin_diff_blobs(struct rev_info *revs,
                              int argc, const char **argv,
                              struct blobinfo *blob)
 {
-       /* Blobs: the arguments are reversed when setup_revisions()
-        * picked them up.
-        */
        unsigned mode = canon_mode(S_IFREG | 0644);
 
        if (argc > 1)
@@ -135,7 +132,7 @@ static int builtin_diff_blobs(struct rev_info *revs,
 
        stuff_change(&revs->diffopt,
                     mode, mode,
-                    blob[1].sha1, blob[0].sha1,
+                    blob[0].sha1, blob[1].sha1,
                     blob[0].name, blob[0].name);
        diffcore_std(&revs->diffopt);
        diff_flush(&revs->diffopt);
@@ -221,7 +218,7 @@ void add_head(struct rev_info *revs)
        add_pending_object(revs, obj, "HEAD");
 }
 
-int cmd_diff(int argc, const char **argv, char **envp)
+int cmd_diff(int argc, const char **argv, const char *prefix)
 {
        int i;
        struct rev_info rev;
@@ -251,7 +248,7 @@ int cmd_diff(int argc, const char **argv, char **envp)
         */
 
        git_config(git_diff_ui_config);
-       init_revisions(&rev);
+       init_revisions(&rev, prefix);
 
        argc = setup_revisions(argc, argv, &rev, NULL);
        if (!rev.diffopt.output_format) {
@@ -346,7 +343,15 @@ int cmd_diff(int argc, const char **argv, char **envp)
                return builtin_diff_index(&rev, argc, argv);
        else if (ents == 2)
                return builtin_diff_tree(&rev, argc, argv, ent);
+       else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
+               /* diff A...B where there is one sane merge base between
+                * A and B.  We have ent[0] == merge-base, ent[1] == A,
+                * and ent[2] == B.  Show diff between the base and B.
+                */
+               return builtin_diff_tree(&rev, argc, argv, ent);
+       }
        else
-               return builtin_diff_combined(&rev, argc, argv, ent, ents);
+               return builtin_diff_combined(&rev, argc, argv,
+                                            ent, ents);
        usage(builtin_diff_usage);
 }