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Re: [PATCH v2 3/3] git-merge-one-file: revise merge error reporting

From
Junio C Hamano <gitster@pobox.com>
Date
Mar 25, 2013, 17:17 UTC
Message-ID
<7vfvzjz9ej.fsf@alter.siamese.dyndns.org>
In-Reply-To
<7vk3ovz9zb.fsf@alter.siamese.dyndns.org>
Junio C Hamano <gitster@pobox.com> writes:
Show 31 quoted lines
> Kevin Bracey <kevin@bracey.fi> writes:
>
>> Commit 718135e improved the merge error reporting for the resolve
>> strategy's merge conflict and permission conflict cases, but led to a
>> malformed "ERROR:  in myfile.c" message in the case of a file added
>> differently.
>>
>> This commit reverts that change, and uses an alternative approach without
>> this flaw.
>>
>> Signed-off-by: Kevin Bracey <kevin@bracey.fi>
>
> We used to treat "Both added differently" as a separate "info"
> message, just like the "Auto-merging" message, and let "content
> conflict" that is an "error" to happen naturally by doing such a
> merge, possibly followed by permission conflict which is another
> kind of "error".  We coalesced these two into a single message.
>
> And this patch breaks them into separate messages.  I am not sure if
> that aspect of the change is desirable.
>
> The source of "malformed" message seems suspicious.  Isn't the root
> cause of $msg being empty that merge-file can (sometimes) cleanly
> merge two files using the phoney base in the "both added
> differently" codepath?
>
> If you resolve that issue by forcing a "conflicted" failure when we
> handle "add/add" conflict, I think the behaviour of the remainder of
> the code is better in the original than the updated one.
>
> Perhaps something like this (I am applying these on 'maint')?

Actually, this one is even better, I think. Again on top of your two patches applied on 'maint'.

Alternatively, we can remove the whole "if $1 is empty, error the merge out" logic, which would be more in line with the spirit of f7d24bbefb06 (merge with /dev/null as base, instead of punting O==empty case, 2005-11-07), but that will be a change in behaviour (a "both side added, slightly differently" case that can cleanly merge will no longer fail), so I am not sure if it is worth it.

-- >8 --
Subject: [PATCH] merge-one-file: force content conflict for "both side added" case

Historically, we tried to be lenient to "both side added, slightly differently" case and as long as the files can be merged using a made-up common ancestor cleanly, since f7d24bbefb06 (merge with /dev/null as base, instead of punting O==empty case, 2005-11-07). This was later further refined to use a better made-up common file with fd66dbf5297a (merge-one-file: use empty- or common-base condintionally in two-stage merge., 2005-11-10), but the spirit has been the same.

But the original fix in f7d24bbefb06 to avoid punging on "both sides added" case had a code to unconditionally error out the merge. When this triggers, even though the content-level merge can be done cleanly, we end up not saying "content conflict" in the message, but still issue the error message, showing "ERROR: in <pathname>".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-merge-one-file.sh | 1 +
 1 file changed, 1 insertion(+)
diff --git a/git-merge-one-file.sh b/git-merge-one-file.sh
index 25d7714..62016f4 100755
--- a/git-merge-one-file.sh
+++ b/git-merge-one-file.sh
@@ -155,6 +155,7 @@ case "${1:-.}${2:-.}${3:-.}" in
 	fi
 	if test -z "$1"
 	then
+		msg='content conflict'
 		ret=1
 	fi
 
-- 
1.8.2-297-g51e0fcd
Previous: Junio C HamanoNext: Junio C Hamano
Message 29 of 40 in “Improve P4Merge mergetool invocation”
  1. 0/2 Improve P4Merge mergetool invocationKevin Bracey, Mar 6, 2013
  2. 1/2 p4merge: swap LOCAL and REMOTE for mergetoolKevin Bracey, Mar 6, 2013
  3. Junio C HamanoMar 7, 2013
  4. Kevin BraceyMar 7, 2013
  5. Junio C HamanoMar 7, 2013
  6. Kevin BraceyMar 7, 2013
  7. Junio C HamanoMar 7, 2013
  8. David AguilarMar 7, 2013
  9. Junio C HamanoMar 7, 2013
  10. 2/2 p4merge: create a virtual base if none availableKevin Bracey, Mar 6, 2013
  11. David AguilarMar 7, 2013
  12. Kevin BraceyMar 7, 2013
  13. Junio C HamanoMar 7, 2013
  14. David AguilarMar 7, 2013
  15. 0/3 Improve P4Merge mergetool invocationKevin Bracey, Mar 9, 2013
  16. 1/3 mergetools/p4merge: swap LOCAL and REMOTEKevin Bracey, Mar 9, 2013
  17. 2/3 mergetools/p4merge: create a base if none availableKevin Bracey, Mar 9, 2013
  18. Junio C HamanoMar 10, 2013
  19. 3/3 git-merge-one-file: revise merge error reportingKevin Bracey, Mar 9, 2013
  20. 1/3 mergetools/p4merge: swap LOCAL and REMOTEKevin Bracey, Mar 13, 2013
  21. 2/3 mergetools/p4merge: create a base if none availableKevin Bracey, Mar 13, 2013
  22. 3/3 git-merge-one-file: revise merge error reportingKevin Bracey, Mar 13, 2013
  23. David AguilarMar 13, 2013
  24. 0/3 git-merge-one-file error reportingKevin Bracey, Mar 24, 2013
  25. 1/3 git-merge-one-file: style cleanupKevin Bracey, Mar 24, 2013
  26. 2/3 git-merge-one-file: send "ERROR:" messages to stderrKevin Bracey, Mar 24, 2013
  27. 3/3 git-merge-one-file: revise merge error reportingKevin Bracey, Mar 24, 2013
  28. Junio C HamanoMar 25, 2013
  29. Junio C HamanoMar 25, 2013
  30. Junio C HamanoMar 25, 2013
  31. Eric SunshineMar 25, 2013
  32. Junio C HamanoMar 13, 2013
  33. Kevin BraceyMar 14, 2013
  34. Junio C HamanoMar 14, 2013
  35. Kevin BraceyMar 14, 2013
  36. Kevin BraceyMar 14, 2013
  37. David AguilarMar 13, 2013
  38. 1/2 mergetools/p4merge: swap LOCAL and REMOTEKevin Bracey, Mar 24, 2013
  39. 2/2 mergetools/p4merge: create a base if none availableKevin Bracey, Mar 24, 2013
  40. Junio C HamanoMar 25, 2013

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