git-diff-tree --stdin: show all parents.

git-diff-tree --stdin ignored second and subsequent parents when
fed git-rev-list --parents output.  Update diff_tree_commit()
function to take a commit object, and pass a fabricated commit
object after grafting the fake parents from diff_tree_stdin().

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/diff-tree.c b/diff-tree.c
index e7410b4..f3280a1 100644 (file)
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -100,23 +100,15 @@ static const char *generate_header(const unsigned char *commit_sha1,
        return this_header;
 }
 
-static int diff_tree_commit(const unsigned char *commit_sha1)
+static int diff_tree_commit(struct commit *commit)
 {
-       struct commit *commit;
        struct commit_list *parents;
-       char name[50];
-       unsigned char sha1[20];
+       unsigned const char *sha1 = commit->object.sha1;
 
-       sprintf(name, "%s^0", sha1_to_hex(commit_sha1));
-       if (get_sha1(name, sha1))
-               return -1;
-       name[40] = 0;
-       commit = lookup_commit(sha1);
-       
        /* Root commit? */
        if (show_root_diff && !commit->parents) {
                header = generate_header(sha1, NULL, commit);
-               diff_root_tree(commit_sha1, "");
+               diff_root_tree(sha1, "");
        }
 
        /* More than one parent? */
@@ -133,7 +125,7 @@ static int diff_tree_commit(const unsigned char *commit_sha1)
        for (parents = commit->parents; parents; parents = parents->next) {
                struct commit *parent = parents->item;
                header = generate_header(sha1, parent->object.sha1, commit);
-               diff_tree_sha1_top(parent->object.sha1, commit_sha1, "");
+               diff_tree_sha1_top(parent->object.sha1, sha1, "");
                if (!header && verbose_header) {
                        header_prefix = "\ndiff-tree ";
                        /*
@@ -145,28 +137,49 @@ static int diff_tree_commit(const unsigned char *commit_sha1)
        return 0;
 }
 
+static int diff_tree_commit_sha1(const unsigned char *sha1)
+{
+       struct commit *commit = lookup_commit_reference(sha1);
+       if (!commit)
+               return -1;
+       return diff_tree_commit(commit);
+}
+
 static int diff_tree_stdin(char *line)
 {
        int len = strlen(line);
-       unsigned char commit[20], parent[20];
-       static char this_header[1000];
-       int abbrev = diff_options.abbrev;
+       unsigned char sha1[20];
+       struct commit *commit;
 
        if (!len || line[len-1] != '\n')
                return -1;
        line[len-1] = 0;
-       if (get_sha1_hex(line, commit))
+       if (get_sha1_hex(line, sha1))
+               return -1;
+       commit = lookup_commit(sha1);
+       if (!commit || parse_commit(commit))
                return -1;
-       if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
-               line[40] = 0;
-               line[81] = 0;
-               sprintf(this_header, "%s (from %s)\n",
-                       diff_unique_abbrev(commit, abbrev),
-                       diff_unique_abbrev(parent, abbrev));
-               header = this_header;
-               return diff_tree_sha1_top(parent, commit, "");
+       if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
+               /* Graft the fake parents locally to the commit */
+               int pos = 41;
+               struct commit_list **pptr, *parents;
+
+               /* Free the real parent list */
+               for (parents = commit->parents; parents; ) {
+                       struct commit_list *tmp = parents->next;
+                       free(parents);
+                       parents = tmp;
+               }
+               commit->parents = NULL;
+               pptr = &(commit->parents);
+               while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
+                       struct commit *parent = lookup_commit(sha1);
+                       if (parent) {
+                               pptr = &commit_list_insert(parent, pptr)->next;
+                       }
+                       pos += 41;
+               }
        }
-       line[40] = 0;
        return diff_tree_commit(commit);
 }
 
@@ -288,7 +301,7 @@ int main(int argc, const char **argv)
                        usage(diff_tree_usage);
                break;
        case 1:
-               diff_tree_commit(sha1[0]);
+               diff_tree_commit_sha1(sha1[0]);
                break;
        case 2:
                diff_tree_sha1_top(sha1[0], sha1[1], "");