# Meaning of double + and - in Gitk's diff pane 6 messages from 2011-03-21 to 2011-03-21. Participants: Dirk Süsserott, Junio C Hamano. Thread: https://gitlist.dev/t/26819 ## Dirk Süsserott, 2011-03-21 18:38 Subject: Meaning of double + and - in Gitk's diff pane Message-ID: <4D879B25.9090300@dirk.my1.cc> URL: https://gitlist.dev/e/4D879B25.9090300%40dirk.my1.cc ``` Hello, I regularly use gitk to get an overview. Great tool. But sometimes it shows me in the diff pane lines preceeded with two + or - signs or they are colored in blue or black or printed in bold. I think this is true for merge commits with conflicts. The simple red - and green + lines are obvious, but is anywhere documented what exactly the other fonts and colors mean? I tried to "Ask The Audience" (which is Google), but try searching for plus and minus! It's pointless. Dirk ``` ## Junio C Hamano, 2011-03-21 19:37 Subject: Re: Meaning of double + and - in Gitk's diff pane Message-ID: <7vr5a0p8n1.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7vr5a0p8n1.fsf%40alter.siamese.dyndns.org In-Reply-To: <4D879B25.9090300@dirk.my1.cc> ``` Dirk Süsserott writes: > I regularly use gitk to get an overview. Great tool. > But sometimes it shows me in the diff pane lines preceeded > with two + or - signs or they are colored in blue or black > or printed in bold. I think this is true for merge commits > with conflicts. Look at the bottom summary of this message for a brief summary: http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15527 If you want to know more about how the multi-way diff is condensed, you would find this message from Linus in the same thread illuminating: http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15600 (Ignore the bottom part where Linus complains about gitk output---the old implementation in gitk has gone long time ago). And also this one, again from Linus: http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15491 ``` ## Dirk Süsserott, 2011-03-21 19:45 Subject: Re: Meaning of double + and - in Gitk's diff pane Message-ID: <4D87AAD6.6000704@dirk.my1.cc> URL: https://gitlist.dev/e/4D87AAD6.6000704%40dirk.my1.cc In-Reply-To: <7vr5a0p8n1.fsf@alter.siamese.dyndns.org> ``` Am 21.03.2011 20:37 schrieb Junio C Hamano: > Dirk Süsserott writes: > >> I regularly use gitk to get an overview. Great tool. >> But sometimes it shows me in the diff pane lines preceeded >> with two + or - signs or they are colored in blue or black >> or printed in bold. I think this is true for merge commits >> with conflicts. > > Look at the bottom summary of this message for a brief summary: > > http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15527 > > If you want to know more about how the multi-way diff is condensed, you > would find this message from Linus in the same thread illuminating: > > http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15600 > > (Ignore the bottom part where Linus complains about gitk output---the old > implementation in gitk has gone long time ago). > > And also this one, again from Linus: > > http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15491 > > -- > To unsubscribe from this list: send the line "unsubscribe git" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Junio, thanks. When I've found the time, I'll probably condense Linus' explanations and submit a documentation patch. It's not explained in the actual git docs, right? ``` ## Junio C Hamano, 2011-03-21 19:49 Subject: Re: Meaning of double + and - in Gitk's diff pane Message-ID: <7vaagop83d.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7vaagop83d.fsf%40alter.siamese.dyndns.org In-Reply-To: <4D87AAD6.6000704@dirk.my1.cc> ``` Dirk Süsserott writes: > Am 21.03.2011 20:37 schrieb Junio C Hamano: >> Dirk Süsserott writes: >> >>> I regularly use gitk to get an overview. Great tool. >>> But sometimes it shows me in the diff pane lines preceeded >>> with two + or - signs or they are colored in blue or black >>> or printed in bold. I think this is true for merge commits >>> with conflicts. >> >> Look at the bottom summary of this message for a brief summary: >> >> http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15527 >> >> If you want to know more about how the multi-way diff is condensed, you >> would find this message from Linus in the same thread illuminating: >> >> http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15600 >> >> (Ignore the bottom part where Linus complains about gitk output---the old >> implementation in gitk has gone long time ago). >> >> And also this one, again from Linus: >> >> http://thread.gmane.org/gmane.comp.version-control.git/15486/focus=15491 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe git" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > Junio, thanks. When I've found the time, I'll probably condense Linus' > explanations and submit a documentation patch. It's not explained > in the actual git docs, right? How about checking "git diff"? The same conclusion should be in there, as I wrote the implementation, docs and the messages there. ``` ## Dirk Süsserott, 2011-03-21 19:57 Subject: Re: Meaning of double + and - in Gitk's diff pane Message-ID: <4D87AD9D.7080501@dirk.my1.cc> URL: https://gitlist.dev/e/4D87AD9D.7080501%40dirk.my1.cc In-Reply-To: <7vaagop83d.fsf@alter.siamese.dyndns.org> ``` Am 21.03.2011 20:49 schrieb Junio C Hamano: >> >> Junio, thanks. When I've found the time, I'll probably condense Linus' >> explanations and submit a documentation patch. It's not explained >> in the actual git docs, right? > > How about checking "git diff"? The same conclusion should be in there, as > I wrote the implementation, docs and the messages there. > Uhh, sorry, I missed that. That was actually what I was searching for. Thanks. ``` ## Junio C Hamano, 2011-03-21 20:40 Subject: Re: Meaning of double + and - in Gitk's diff pane Message-ID: <7vwrjsnr5z.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7vwrjsnr5z.fsf%40alter.siamese.dyndns.org In-Reply-To: <4D87AD9D.7080501@dirk.my1.cc> ``` Dirk Süsserott writes: > Am 21.03.2011 20:49 schrieb Junio C Hamano: >>> >>> Junio, thanks. When I've found the time, I'll probably condense Linus' >>> explanations and submit a documentation patch. It's not explained >>> in the actual git docs, right? >> >> How about checking "git diff"? The same conclusion should be in there, as >> I wrote the implementation, docs and the messages there. >> > Uhh, sorry, I missed that. That was actually what I was searching for. Hmm... re-reading "git diff --help" and looking at the section on combined diff, I notice that we talk about how to understand its output, but we don't say under what rule the --cc option condenses what would be produced with the -c option. Perhaps we would need a patch after all at the end of Documentation/diff-generate-patch.txt file. Here is a quick attempt. Documentation/diff-generate-patch.txt | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/Documentation/diff-generate-patch.txt b/Documentation/diff-generate-patch.txt index c57460c..20a603d 100644 --- a/Documentation/diff-generate-patch.txt +++ b/Documentation/diff-generate-patch.txt @@ -183,3 +183,21 @@ parents). When shown by `git diff-files -c`, it compares the two unresolved merge parents with the working tree file (i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka "their version"). + +The "combined" format (`-c` option) shows the diff to the result (i.e. the +result of the merge, or the file in the working tree during a conflict +resolution) from two or more originals (i.e. parents of the merge or +branches being merged) combined, but it often shows many trivial changes +that the result takes the change from a single original verbatim. The +"dense combined" format (`--cc` option) removes such hunks with only +"trivial" changes. A hunk that has only two versions (or less) in the +original (in a usual two-parent merge, this always is the case, simply +because there are only two originals) and whose result matches exactly one +of the originals, is considered "trivial" and is omitted from the output +in the "dense combined" format. In the previous illustration of a +combined diff on `describe.c` file, there are two originals, one that had +the describe function with a single `char *arg` parameter, and the other +with two parameters, but the result matches neither of them, hence it is +not "trivial" and the hunk appears in the output. + + ```