[PATCH v2 0/2] Make git rebase -r's label generation more resilient

Those labels must be valid ref names, and therefore valid file names. The initial patch came in via Git for Windows.

Change since v1:

 * moved the entire sanitizing logic to label_oid(), as a preparatory step.

Johannes Schindelin (1):
  rebase-merges: move labels' whitespace mangling into `label_oid()`

Matthew Rogers (1):
  rebase -r: let `label` generate safer labels

 sequencer.c              | 72 +++++++++++++++++++++++++---------------
 t/t3430-rebase-merges.sh |  6 ++++
 2 files changed, 51 insertions(+), 27 deletions(-)

base-commit: d9f6f3b6195a0ca35642561e530798ad1469bd41
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-327%2Fdscho%2Ffix-rebase-r-labels-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-327/dscho/fix-rebase-r-labels-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/327

Range-diff vs v1:

 -:  ---------- > 1:  3f4d086e80 rebase-merges: move labels' whitespace mangling into `label_oid()`
 1:  4a02c38442 ! 2:  adc22c8ba2 rebase -r: let `label` generate safer labels
     @@ -1,14 +1,15 @@
     -Author: Matt R <mattr94@gmail.com>
     +Author: Matthew Rogers <mattr94@gmail.com>
      
          rebase -r: let `label` generate safer labels
      
          The `label` todo command in interactive rebases creates temporary refs
          in the `refs/rewritten/` namespace. These refs are stored as loose refs,
          i.e. as files in `.git/refs/rewritten/`, therefore they have to conform
     -    with file name limitations on the current filesystem.
     +    with file name limitations on the current filesystem in addition to the
     +    accepted ref format.
      
     -    This poses a problem in particular on NTFS/FAT, where e.g. the colon
     -    character is not a valid part of a file name.
     +    This poses a problem in particular on NTFS/FAT, where e.g. the colon,
     +    double-quote and pipe characters are disallowed as part of a file name.
      
          Let's safeguard against this by replacing not only white-space
          characters by dashes, but all non-alpha-numeric ones.
     @@ -23,8 +24,8 @@
       --- a/sequencer.c
       +++ b/sequencer.c
      @@
     - 		else
     - 			strbuf_addbuf(&label, &oneline);
     + 	} else {
     + 		struct strbuf *buf = &state->buf;
       
      +		/*
      +		 * Sanitize labels by replacing non-alpha-numeric characters
     @@ -36,18 +37,26 @@
      +		 * in file names. We do not validate the UTF-8 here, that's not
      +		 * the job of this function.
      +		 */
     - 		for (p1 = label.buf; *p1; p1++)
     --			if (isspace(*p1))
     -+			if (!(*p1 & 0x80) && !isalnum(*p1))
     - 				*(char *)p1 = '-';
     + 		for (; *label; label++)
     +-			strbuf_addch(buf, isspace(*label) ? '-' : *label);
     ++			if ((*label & 0x80) || isalnum(*label))
     ++				strbuf_addch(buf, *label);
     ++			/* avoid leading dash and double-dashes */
     ++			else if (buf->len && buf->buf[buf->len - 1] != '-')
     ++				strbuf_addch(buf, '-');
     ++		if (!buf->len) {
     ++			strbuf_addstr(buf, "rev-");
     ++			strbuf_add_unique_abbrev(buf, oid, default_abbrev);
     ++		}
     + 		label = buf->buf;
       
     - 		strbuf_reset(&buf);
     + 		if ((buf->len == the_hash_algo->hexsz &&
      
       diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
       --- a/t/t3430-rebase-merges.sh
       +++ b/t/t3430-rebase-merges.sh
      @@
     - 	test_path_is_missing .git/MERGE_HEAD
     + 	test_cmp expect G.t
       '
       
      +test_expect_success '--rebase-merges with commit that can generate bad characters for filename' '
     @@ -55,4 +64,5 @@
      +	git merge -m "colon: this should work" G &&
      +	git rebase --rebase-merges --force-rebase E
      +'
     ++
       test_done