Re: [PATCH v3 2/7] archive --add-file-with-contents: allow paths containing colons

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Elijah,

On Fri, 6 May 2022, Elijah Newren wrote:

> On Wed, May 4, 2022 at 8:25 AM Johannes Schindelin via GitGitGadget
> <gitgitgadget@gmail.com> wrote:
> >
> > From: Johannes Schindelin <johannes.schindelin@gmx.de>
> >
> > By allowing the path to be enclosed in double-quotes, we can avoid
> > the limitation that paths cannot contain colons.
> >
> > Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> > ---
> >  Documentation/git-archive.txt | 13 +++++++++----
> >  archive.c                     | 34 +++++++++++++++++++++++++++++-----
> >  t/t5003-archive-zip.sh        |  8 ++++++++
> >  3 files changed, 46 insertions(+), 9 deletions(-)
> >
> > diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
> > index a0edc9167b2..1789ce4c232 100644
> > --- a/Documentation/git-archive.txt
> > +++ b/Documentation/git-archive.txt
> > @@ -67,10 +67,15 @@ OPTIONS
> >         by concatenating the value for `--prefix` (if any) and the
> >         basename of <file>.
> >  +
> > -The `<path>` cannot contain any colon, the file mode is limited to
> > -a regular file, and the option may be subject to platform-dependent
> > -command-line limits. For non-trivial cases, write an untracked file
> > -and use `--add-file` instead.
> > +The `<path>` argument can start and end with a literal double-quote
> > +character. In this case, the backslash is interpreted as escape
> > +character. The path must be quoted if it contains a colon, to avoid
> > +the colon from being misinterpreted as the separator between the
> > +path and the contents.
>
> The path must also be quoted if it begins or ends with a double-quote, right?

True.

> Also, would people want to be able to pass a pathname from the output
> of e.g. `git ls-files -o`, which may quote additional characters?

Also true.

> > ++
> > +The file mode is limited to a regular file, and the option may be
> > +subject to platform-dependent command-line limits. For non-trivial
> > +cases, write an untracked file and use `--add-file` instead.
> >
> >  --worktree-attributes::
> >         Look for attributes in .gitattributes files in the working tree
> > diff --git a/archive.c b/archive.c
> > index d798624cd5f..3b751027143 100644
> > --- a/archive.c
> > +++ b/archive.c
> > @@ -533,13 +533,37 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
> >                         die(_("Not a regular file: %s"), path);
> >                 info->content = NULL; /* read the file later */
> >         } else {
> > -               const char *colon = strchr(arg, ':');
> >                 char *p;
> >
> > -               if (!colon)
> > -                       die(_("missing colon: '%s'"), arg);
> > +               if (*arg != '"') {
> > +                       const char *colon = strchr(arg, ':');
> > +
> > +                       if (!colon)
> > +                               die(_("missing colon: '%s'"), arg);
> > +                       p = xstrndup(arg, colon - arg);
> > +                       arg = colon + 1;
> > +               } else {
> > +                       struct strbuf buf = STRBUF_INIT;
> > +                       const char *orig = arg;
> > +
> > +                       for (;;) {
> > +                               if (!*(++arg))
> > +                                       die(_("unclosed quote: '%s'"), orig);
> > +                               if (*arg == '"')
> > +                                       break;
> > +                               if (*arg == '\\' && *(++arg) == '\0')
> > +                                       die(_("trailing backslash: '%s"), orig);
> > +                               else
> > +                                       strbuf_addch(&buf, *arg);
> > +                       }
> > +
> > +                       if (*(++arg) != ':')
> > +                               die(_("missing colon: '%s'"), orig);
> > +
> > +                       p = strbuf_detach(&buf, NULL);
> > +                       arg++;
> > +               }
>
> Should we use unquote_c_style() here instead of rolling another parser
> to do unquoting?  That would have the added benefit of allowing people
> to use filenames from the output of various git commands that do
> special quoting -- such as octal sequences for non-ascii characters.

Yep, let's do that. I somehow missed that function while glimpsing at
`quote.h`.

Thank you for your review!
Dscho

> >
> > -               p = xstrndup(arg, colon - arg);
> >                 if (!args->prefix)
> >                         path = p;
> >                 else {
> > @@ -548,7 +572,7 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
> >                 }
> >                 memset(&info->stat, 0, sizeof(info->stat));
> >                 info->stat.st_mode = S_IFREG | 0644;
> > -               info->content = xstrdup(colon + 1);
> > +               info->content = xstrdup(arg);
> >                 info->stat.st_size = strlen(info->content);
> >         }
> >         item = string_list_append_nodup(&args->extra_files, path);
> > diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
> > index 8ff1257f1a0..5b8bbfc2692 100755
> > --- a/t/t5003-archive-zip.sh
> > +++ b/t/t5003-archive-zip.sh
> > @@ -207,13 +207,21 @@ check_zip with_untracked
> >  check_added with_untracked untracked untracked
> >
> >  test_expect_success UNZIP 'git archive --format=zip --add-file-with-content' '
> > +       if test_have_prereq FUNNYNAMES
> > +       then
> > +               QUOTED=quoted:colon
> > +       else
> > +               QUOTED=quoted
> > +       fi &&
> >         git archive --format=zip >with_file_with_content.zip \
> > +               --add-file-with-content=\"$QUOTED\": \
> >                 --add-file-with-content=hello:world $EMPTY_TREE &&
> >         test_when_finished "rm -rf tmp-unpack" &&
> >         mkdir tmp-unpack && (
> >                 cd tmp-unpack &&
> >                 "$GIT_UNZIP" ../with_file_with_content.zip &&
> >                 test_path_is_file hello &&
> > +               test_path_is_file $QUOTED &&
> >                 test world = $(cat hello)
> >         )
> >  '
> > --
> > gitgitgadget
>
>