Re: bug: `git log --grep ... --invert-grep --author=...` negates / ignores --author

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Wed, May 31, 2017 at 11:40 PM, Jeff King <peff@peff.net> wrote:
> On Wed, May 31, 2017 at 08:08:54PM +0200, Ævar Arnfjörð Bjarmason wrote:
>
>> $ git log --grep=bar --author=Ævar --pretty=format:%an -100 origin/pu
>> |sort|uniq -c|sort -nr
>> 5 Ævar Arnfjörð Bjarmason
>>
>> $ git log --author=Ævar --pretty=format:%an -100 origin/pu |sort|uniq
>> -c|sort -nr
>> 100 Ævar Arnfjörð Bjarmason
>>
>> $ git log --grep=bar --invert-grep --author=Ævar --pretty=format:%an
>> -100 origin/pu |sort|uniq -c|sort -nr
>>      78 Junio C Hamano
>>      14 Jeff King
>>       2 Andreas Heiduk
>>       1 Sahil Dua
>>       1 Rikard Falkeborn
>>       1 Johannes Sixt
>>       1 Johannes Schindelin
>>       1 Ben Peart
>>       1 Ævar Arnfjörð Bjarmason
>>
>> That last command should only find my commits, but instead --author is
>> discarded.
>
> I would have thought that the last command wouldn't find _any_ of your
> commits. Don't we consider --author a greppable pattern and invert it?

There's two unrelated things going on here AFAICT:

* Anthony expected --author to be inverted by --invert-grep, but this
is not how it's documented, it's *only* for inverting the --grep
pattern: "Limit the commits output to ones with log message that do
not match the pattern specified with --grep=<pattern>."

* The --author filter should be applied un-inverted, but isn't, it's
seemingly just ignored in the presence of --grep, actually mostly
ignored, this is bizarre:

$ diff -ru <(git log --grep=bar --invert-grep --pretty=format:%an -100
origin/pu |sort|uniq -c|sort -nr) <(git log --grep=bar --invert-grep
--pretty=format:%an -100 --author=WeMostlyIgnoreThisButNotReally
origin/pu |sort|uniq -c|sort -nr)
--- /dev/fd/63  2017-06-01 21:44:08.952583804 +0200
+++ /dev/fd/62  2017-06-01 21:44:08.952583804 +0200
@@ -1,6 +1,6 @@
-     66 Junio C Hamano
+     65 Junio C Hamano
      10 Jeff King
-      8 Stefan Beller
+      9 Stefan Beller
       5 Lars Schneider
       2 SZEDER Gábor
       1 Tyler Brazier


> By itself:
>
>   $ git log --author=Ævar --invert-grep --format=%an -100 origin/pu |
>     sort | uniq -c | sort -rn
>        79 Junio C Hamano
>         8 Stefan Beller
>         8 Jeff King
>         1 Sahil Dua
>         1 Rikard Falkeborn
>         1 Johannes Sixt
>         1 Johannes Schindelin
>         1 Andreas Heiduk
>
> So that makes sense from the "--author is invertable" world-view.
>
> But I'm puzzled that you show up at all when --grep=bar is added (and
> moreover, that we get _one_ commit from you, not the 5 found in your
> initial command). That seems like a bug.

I think that's the only thing that's not a bug, i.e. we just find 1
match in the first 100 (note -100), sorry for the confusing example.

Anyway, much of the above may be incorrect, I haven't dug deeply
beyond just finding that something's funny going on and we definitely
have *some* bugs here.