Merge branch 'jc/mention-tracking-for-pull-default'

[git.git] / pretty.c

diff --git a/pretty.c b/pretty.c
index c6753494386d4d1043e87babcc97f8499177cb5a..eae57ad9d7f3b06a5a76f9d934825f9824def477 100644 (file)
--- a/pretty.c
+++ b/pretty.c
@@ -592,18 +592,59 @@ char *logmsg_reencode(const struct commit *commit,
        char *msg = commit->buffer;
        char *out;
 
+       if (!msg) {
+               enum object_type type;
+               unsigned long size;
+
+               msg = read_sha1_file(commit->object.sha1, &type, &size);
+               if (!msg)
+                       die("Cannot read commit object %s",
+                           sha1_to_hex(commit->object.sha1));
+               if (type != OBJ_COMMIT)
+                       die("Expected commit for '%s', got %s",
+                           sha1_to_hex(commit->object.sha1), typename(type));
+       }
+
        if (!output_encoding || !*output_encoding)
                return msg;
        encoding = get_header(commit, msg, "encoding");
        use_encoding = encoding ? encoding : utf8;
-       if (same_encoding(use_encoding, output_encoding))
-               if (encoding) /* we'll strip encoding header later */
-                       out = xstrdup(commit->buffer);
-               else
-                       return msg; /* nothing to do */
-       else
-               out = reencode_string(commit->buffer,
-                                     output_encoding, use_encoding);
+       if (same_encoding(use_encoding, output_encoding)) {
+               /*
+                * No encoding work to be done. If we have no encoding header
+                * at all, then there's nothing to do, and we can return the
+                * message verbatim (whether newly allocated or not).
+                */
+               if (!encoding)
+                       return msg;
+
+               /*
+                * Otherwise, we still want to munge the encoding header in the
+                * result, which will be done by modifying the buffer. If we
+                * are using a fresh copy, we can reuse it. But if we are using
+                * the cached copy from commit->buffer, we need to duplicate it
+                * to avoid munging commit->buffer.
+                */
+               out = msg;
+               if (out == commit->buffer)
+                       out = xstrdup(out);
+       }
+       else {
+               /*
+                * There's actual encoding work to do. Do the reencoding, which
+                * still leaves the header to be replaced in the next step. At
+                * this point, we are done with msg. If we allocated a fresh
+                * copy, we can free it.
+                */
+               out = reencode_string(msg, output_encoding, use_encoding);
+               if (out && msg != commit->buffer)
+                       free(msg);
+       }
+
+       /*
+        * This replacement actually consumes the buffer we hand it, so we do
+        * not have to worry about freeing the old "out" here.
+        */
        if (out)
                out = replace_encoding_header(out, output_encoding);