"ZheNing Hu via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > Subject: Re: [PATCH v10 1/2] [GSOC] docs: correct descript of trailer.<token>.command s/descript/&ion/ (no need to resend only to fix this). > diff --git a/Documentation/git-interpret-trailers.txt b/Documentation/git-interpret-trailers.txt > index 96ec6499f001..6f2a7a130464 100644 > --- a/Documentation/git-interpret-trailers.txt > +++ b/Documentation/git-interpret-trailers.txt > @@ -232,25 +232,30 @@ trailer.<token>.ifmissing:: > that option for trailers with the specified <token>. > > trailer.<token>.command:: > + This option can be used to specify a shell command that will be called: > + once to automatically add a trailer with the specified <token>, and then > + each time a '--trailer <token>=<value>' argument to modify the <value> of > + the trailer that this option would produce. > + > +When the specified command is first called to add a trailer > +with the specified <token>, the behavior is as if a special > +'--trailer <token>=<value>' argument was added at the beginning > +of the "git interpret-trailers" command, where <value> > +is taken to be the standard output of the command with any > +leading and trailing whitespace trimmed off. > + > +If some '--trailer <token>=<value>' arguments are also passed > +on the command line, the command is called again once for each > +of these arguments with the same <token>. And the <value> part > +of these arguments, if any, will be used to replace the first > +occurrence of substring `$ARG` in the command. This way the > +command can produce a <value> computed from the <value> passed > +in the '--trailer <token>=<value>' argument. > + Makes quite a lot of sense. I wouldn't have got confused by the behaviour of .command if it were documented like the above from day one. Very nice. > +For consistency, the first occurrence of substring `$ARG` is > +also replaced, this time with the empty string, in the command > +when the command is first called to add a trailer with the > +specified <token>. OK, so "for consistency" is about consistency between the "execute once first without being asked" case (where there is no plausible source of $ARG), and "execute because we were asked by a command line option (where we are given <value> to replace $ARG). Makes sense. Will queue. Thanks.
