unpack_loose_rest(): simplify error handling

Inflating a loose object is considered successful only if we got
Z_STREAM_END and there were no more bytes. We check both of those
conditions and return success, but then have to check them a second time
to decide which error message to produce.

I.e., we do something like this:

  if (!error_1 && !error_2)
          ...return success...

  if (error_1)
          ...handle error1...
  else if (error_2)
          ...handle error2...
  ...common error handling...

This repetition was the source of a small bug fixed in an earlier commit
(our Z_STREAM_END check was not the same in the two conditionals).

Instead we can chain them all into a single if/else cascade, which
avoids repeating ourselves:

  if (error_1)
          ...handle error1...
  else if (error_2)
          ...handle error2....
  else
          ...return success...
  ...common error handling...

Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

object-file.c

@@ -1347,15 +1347,15 @@ static void *unpack_loose_rest(git_zstream *stream,
 			obj_read_lock();
 		}
 	}
-	if (status == Z_STREAM_END && !stream->avail_in) {
-		return buf;
-	}
 
 	if (status != Z_STREAM_END)
 		error(_("corrupt loose object '%s'"), oid_to_hex(oid));
 	else if (stream->avail_in)
 		error(_("garbage at end of loose object '%s'"),
 		      oid_to_hex(oid));
+	else
+		return buf;
+
 	free(buf);
 	return NULL;
 }