Hi, On Sat, Mar 08, 2008 at 06:17:26PM +0100, Clemens Buchacher wrote: > If git-merge-recursive attempts to merge two empty new files with > different executable flags, eventually xdl_merge() is called and produces > empty diffs for both files and therefore does not choose either file as > successor. Make xdl_merge() choose one of the files instead. On Sat, Mar 08, 2008 at 06:51:48PM +0100, Johannes Schindelin wrote: > On Sat, 8 Mar 2008, Clemens Buchacher wrote: > > I do not understand why, but this does not happen if the file > > permissions are the same. > > I think this is the biggest problem. > > > t/t6031-merge-recursive.sh | 23 +++++++++++++++++++++++ > > xdiff/xmerge.c | 30 ++++++++++++++---------------- > > ... because xdiff/xmerge.c is definitely the wrong place to "fix" this > issue. xdl_merge() does not even _know_ about permissions. After analyzing the problem in greater detail, I have to disagree. It is true, of course, that xdl_merge() does not and should not know about permissions at all. However, the bug is still in xdl_merge(). Different permissions are only the trigger of the problem, because only then will xdl_merge() be called at all. What happens is this. Before looking at the file contents directly merge_trees() attempts to resolve the merge trivially. If both sha1 and mode of the head and remote entries match, the merge will be resolved as per case #5ALT (see Documentation/trivial-merge.txt), i.e. head is chosen as the merge result. If either sha1 _or_ mode differ between the head and remote entries, however, merge_trees() will use xdl_merge() to merge the file content and the remote entry's mode will be chosen as result mode. One could argue that it would be better to mark the mismatching permissions as a conflict. However, this is how the merge currently silently succeeds _unless_ both files are empty. If they are, xdl_merge() will effectively exit with an error status and git-merge-recursive will fail with an internal error (as shown in the testcase). In any case, I think it is reasonable to expect xdl_merge() to work with empty files. Whether or not the current "mode merging" behavior is desired is a different matter. Regards, Clemens -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
