commit: give advice on empty amend

diff --git a/merge-recursive.c b/merge-recursive.c
index 22a31ed5ff5d1affd54da43769a3982ba2ec1b75..917397ca7a0c3a702681e1c3e93eb385bb6f28fb 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -21,15 +21,17 @@
 #include "merge-recursive.h"
 #include "dir.h"
 
-static struct tree *shift_tree_object(struct tree *one, struct tree *two)
+static struct tree *shift_tree_object(struct tree *one, struct tree *two,
+                                     const char *subtree_shift)
 {
        unsigned char shifted[20];
 
-       /*
-        * NEEDSWORK: this limits the recursion depth to hardcoded
-        * value '2' to avoid excessive overhead.
-        */
-       shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
+       if (!*subtree_shift) {
+               shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
+       } else {
+               shift_tree_by(one->object.sha1, two->object.sha1, shifted,
+                             subtree_shift);
+       }
        if (!hashcmp(two->object.sha1, shifted))
                return two;
        return lookup_tree(shifted);
@@ -597,23 +599,6 @@ struct merge_file_info
                 merge:1;
 };
 
-static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
-{
-       unsigned long size;
-       enum object_type type;
-
-       if (!hashcmp(sha1, null_sha1)) {
-               mm->ptr = xstrdup("");
-               mm->size = 0;
-               return;
-       }
-
-       mm->ptr = read_sha1_file(sha1, &type, &size);
-       if (!mm->ptr || type != OBJ_BLOB)
-               die("unable to read blob object %s", sha1_to_hex(sha1));
-       mm->size = size;
-}
-
 static int merge_3way(struct merge_options *o,
                      mmbuffer_t *result_buf,
                      struct diff_filespec *one,
@@ -623,24 +608,46 @@ static int merge_3way(struct merge_options *o,
                      const char *branch2)
 {
        mmfile_t orig, src1, src2;
-       char *name1, *name2;
+       char *base_name, *name1, *name2;
        int merge_status;
+       int favor;
+
+       if (o->call_depth)
+               favor = 0;
+       else {
+               switch (o->recursive_variant) {
+               case MERGE_RECURSIVE_OURS:
+                       favor = XDL_MERGE_FAVOR_OURS;
+                       break;
+               case MERGE_RECURSIVE_THEIRS:
+                       favor = XDL_MERGE_FAVOR_THEIRS;
+                       break;
+               default:
+                       favor = 0;
+                       break;
+               }
+       }
 
-       if (strcmp(a->path, b->path)) {
+       if (strcmp(a->path, b->path) ||
+           (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
+               base_name = o->ancestor == NULL ? NULL :
+                       xstrdup(mkpath("%s:%s", o->ancestor, one->path));
                name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
                name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
        } else {
+               base_name = o->ancestor == NULL ? NULL :
+                       xstrdup(mkpath("%s", o->ancestor));
                name1 = xstrdup(mkpath("%s", branch1));
                name2 = xstrdup(mkpath("%s", branch2));
        }
 
-       fill_mm(one->sha1, &orig);
-       fill_mm(a->sha1, &src1);
-       fill_mm(b->sha1, &src2);
+       read_mmblob(&orig, one->sha1);
+       read_mmblob(&src1, a->sha1);
+       read_mmblob(&src2, b->sha1);
 
-       merge_status = ll_merge(result_buf, a->path, &orig,
+       merge_status = ll_merge(result_buf, a->path, &orig, base_name,
                                &src1, name1, &src2, name2,
-                               o->call_depth);
+                               (!!o->call_depth) | (favor << 1));
 
        free(name1);
        free(name2);
@@ -1201,9 +1208,9 @@ int merge_trees(struct merge_options *o,
 {
        int code, clean;
 
-       if (o->subtree_merge) {
-               merge = shift_tree_object(head, merge);
-               common = shift_tree_object(head, common);
+       if (o->subtree_shift) {
+               merge = shift_tree_object(head, merge, o->subtree_shift);
+               common = shift_tree_object(head, common, o->subtree_shift);
        }
 
        if (sha_eq(common->object.sha1, merge->object.sha1)) {
@@ -1340,6 +1347,7 @@ int merge_recursive(struct merge_options *o,
        if (!o->call_depth)
                read_cache();
 
+       o->ancestor = "merged common ancestors";
        clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
                            &mrtree);