Try normalizing files to avoid delete/modify conflicts when merging

diff --git a/merge-recursive.c b/merge-recursive.c
index 917397ca7a0c3a702681e1c3e93eb385bb6f28fb..5ad8fc9e7ea7c6653e28343ccc0fa0c260e3affd 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -409,7 +409,7 @@ static int remove_file(struct merge_options *o, int clean,
                        return -1;
        }
        if (update_working_directory) {
-               if (remove_path(path) && errno != ENOENT)
+               if (remove_path(path))
                        return -1;
        }
        return 0;
@@ -1056,6 +1056,53 @@ static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
        return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
 }
 
+static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
+{
+       void *buf;
+       enum object_type type;
+       unsigned long size;
+       buf = read_sha1_file(sha1, &type, &size);
+       if (!buf)
+               return error("cannot read object %s", sha1_to_hex(sha1));
+       if (type != OBJ_BLOB) {
+               free(buf);
+               return error("object %s is not a blob", sha1_to_hex(sha1));
+       }
+       strbuf_attach(dst, buf, size, size + 1);
+       return 0;
+}
+
+static int blob_unchanged(const unsigned char *o_sha,
+                         const unsigned char *a_sha,
+                         const char *path)
+{
+       struct strbuf o = STRBUF_INIT;
+       struct strbuf a = STRBUF_INIT;
+       int ret = 0; /* assume changed for safety */
+
+       if (sha_eq(o_sha, a_sha))
+               return 1;
+       if (!merge_renormalize)
+               return 0;
+
+       assert(o_sha && a_sha);
+       if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
+               goto error_return;
+       /*
+        * Note: binary | is used so that both renormalizations are
+        * performed.  Comparison can be skipped if both files are
+        * unchanged since their sha1s have already been compared.
+        */
+       if (renormalize_buffer(path, o.buf, o.len, &o) |
+           renormalize_buffer(path, a.buf, o.len, &a))
+               ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
+
+error_return:
+       strbuf_release(&o);
+       strbuf_release(&a);
+       return ret;
+}
+
 /* Per entry merge function */
 static int process_entry(struct merge_options *o,
                         const char *path, struct stage_data *entry)
@@ -1075,8 +1122,8 @@ static int process_entry(struct merge_options *o,
        if (o_sha && (!a_sha || !b_sha)) {
                /* Case A: Deleted in one */
                if ((!a_sha && !b_sha) ||
-                   (sha_eq(a_sha, o_sha) && !b_sha) ||
-                   (!a_sha && sha_eq(b_sha, o_sha))) {
+                   (!b_sha && blob_unchanged(o_sha, a_sha, path)) ||
+                   (!a_sha && blob_unchanged(o_sha, b_sha, path))) {
                        /* Deleted in both or deleted in one and
                         * unchanged in the other */
                        if (a_sha)