Re: p4Merge bundled command and the behaviour with files (same name) added on different branches.
From: David Aguilar <hidden>
Date: 2016-06-15 22:50:59
On Mon, Apr 04, 2011 at 09:55:41AM +0100, Ciaran wrote:
[...] We would expect a 'both added' merge conflict (both the other branch, and the master branch added the file named bar.txt, but with different content.) This is all good and right. So in a system configured to use p4merge as the mergetool, one fires up with 'git mergetool' What happens now is p4merge starts and tells us: Base: bar.txt.LOCAL.<num1>.txt Left: bar.txt.LOCAL.<num1>.txt Differences from base: 0 Right: bar.txt.LOCAL.<num2>.txt Differences from base: 1 Merge: bar.txt Conflicts:0 Presenting the left + right options on top of each other in the result window (which may be correct) and leaving the save button disabled (grayed out) If at this point one closes the window without editing the presented (apparently merged) file, then nothing will be saved to disk and we will see: bar.txt seems unchanged. Was the merge successful? [y/n] In the console. Which Git wise is correct, that is exactly right, the p4merge tool hasn't made any actual changes to the underlying file. This behaviour seems confusing to me (the p4merge client behaviour, *not* Git's) I believe it is because in the case where there is no logical base between two files the local one is arbritrarily chosen, and p4merge *thinks* that this is equal to the merge result and has nothing to persist. I have attached a patch that resolves the issue for me (e.g. introduces the behaviour I expect) by passing a reference to an empty file in the case where there is no meaningful base. Unfortunately I don't understand enough to say whether this change is correct or not and would value feedback on it. Many thanks - Cj.
Thanks. If this patch were for actual consideration you would inline the patch instead of sending an attachment as described in Documentation/SubmittingPatches. Marking the subject line with "[RFC PATCH]" lets us know that you're interested in feedback. I have a few questions below.
quoted hunk ↗ jump to hunk
index fb3f52b..3e486dc 100644--- a/git-mergetool--lib.sh +++ b/git-mergetool--lib.sh@@ -262,7 +262,9 @@ run_merge_tool () { if $base_present; then "$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" "$MERGED" else - "$merge_tool_path" "$LOCAL" "$LOCAL" "$REMOTE" "$MERGED" + touch ".empty" + "$merge_tool_path" ".empty" "$LOCAL" "$REMOTE" "$MERGED" + rm ".empty" fi check_unchanged else--
What if the user has a file called '.empty' in their repository? What if the user Ctrl-C's out of mergetool -- does a stale .empty file get left behind? Does it work if we pass /dev/null instead? Is such a strategy portable to Windows? If /dev/null doesn't work, would it be better if the empty file were given a different name? Maybe something like foo.EMPTY.<num>.txt? -- David