Philippe Blain reported in https://lore.kernel.org/git/ecf6f5be-22ca-299f-a8f1-bda38e5ca246@xxxxxxxxx that there is a problem when running the built-in version of git add -p with diff-so-fancy [https://github.com/so-fancy/diff-so-fancy] as diff colorizer. The symptom is this: error: could not parse colored hunk header '?[36m?[1m?[38;5;13m@ file:1 @?[1m?[0m' This patch series addresses that and should fix https://github.com/so-fancy/diff-so-fancy/issues/437 Changes since v3: * Instead of deviating from how the Perl version of git add -p did things, we now teach the built-in version to display hunk headers verbatim when no line range could be parsed out (instead of showing the line range anyways). This was a very good idea of Phillip's, dramatically simplifying the patch series. * Also, this iteration drops the first patch that claims to redefine what we consider bogus, but only hides an off-by-one. In its stead, there is now a patch that fixes said off-by-one. Changes since v2: * Added the appropriate "Reported-by" trailer to the commit message. * Split out the logic to insert a space between the colored line range and the extra information, if needed. * That logic was now corrected to see whether that space is really needed. * To verify that the logic does what we need it to do, the added regression test now specifically tests for that (single) extra space that we want to be inserted. * Reworded a stale comment that claimed that we might suppress the entire colored hunk header (which we no longer do). * Rebased to the current tip of the main branch to avoid a merge conflict with 716c1f649e3 (pipe_command(): mark stdin descriptor as non-blocking, 2022-08-17). Changes since v1: * Added a commit to ignore dirty submodules just like the Perl version does. Johannes Schindelin (3): add -p: detect more mismatches between plain vs colored diffs add -p: gracefully handle unparseable hunk headers in colored diffs add -p: ignore dirty submodules add-patch.c | 50 +++++++++++++++++++++----------------- t/t3701-add-interactive.sh | 27 ++++++++++++++++++-- 2 files changed, 53 insertions(+), 24 deletions(-) base-commit: 07ee72db0e97b5c233f8ada0abb412248c2f1c6f Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1336%2Fdscho%2Fdiff-so-fancy-v4 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1336/dscho/diff-so-fancy-v4 Pull-Request: https://github.com/gitgitgadget/git/pull/1336 Range-diff vs v3: 1: a01fa5d25e4 ! 1: 25187c3a3c2 t3701: redefine what is "bogus" output of a diff filter @@ Metadata Author: Johannes Schindelin <Johannes.Schindelin@xxxxxx> ## Commit message ## - t3701: redefine what is "bogus" output of a diff filter + add -p: detect more mismatches between plain vs colored diffs When parsing the colored version of a diff, the interactive `add` command really relies on the colored version having the same number of - lines as the non-colored version. That is an invariant. - - However, in the 'detect bogus diffFilter output' test case in t3701, we - essentially required a hunk header that contains parseable `@@ ... @@` - hunk headers, and called all colored diffs without such hunks bogus. - - The reason for this is that we would like to show the users the adjusted - hunk headers _including_ the extra part after the `@@ ... @@` - information, which usually contains things like the function name or - soms such. - - Now, there is a _very_ popular diff colorizer called `diff-so-fancy` - that does not produce such colored diffs as the built-in `add` command - expects. Nevertheless, the Perl variant of the `add` command handles - those nicely, essentially by ignoring the hunk header and saying "there - is nothing else we can show except the original hunk header, even if we - had to adjust the line range and the original hunk header might get that - wrong". - - In preparation for teaching the built-in interactive `add` to be a bit - more lenient, let's change the 'detect bogus diffFilter output' test - case so that it verifies that a mismatched number of lines causes the - command to error out, but not an unparseable hunk header. + lines as the plain (uncolored) version. That is an invariant. + + We already have code to verify correctly when the colored diff has less + lines than the plain diff. Modulo an off-by-one bug: If the last diff + line has no matching colored one, the code pretends to succeed, still. + + To make matters worse, when we adjusted the test in 1e4ffc765db (t3701: + adjust difffilter test, 2020-01-14), we did not catch this because `add + -p` fails for a _different_ reason: it does not find any colored hunk + header that contains a parseable line range. + + If we change the test case so that the line range _can_ be parsed, the + bug is exposed. + + Let's address all of the above by + + - fixing the off-by-one, + + - adjusting the test case to allow `add -p` to parse the line range + + - making the test case more stringent by verifying that the expected + error message is shown + + Also adjust a misleading code comment about the now-fixed code. Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> + ## add-patch.c ## +@@ add-patch.c: static int parse_diff(struct add_p_state *s, const struct pathspec *ps) + if (colored_eol) + colored_p = colored_eol + 1; + else if (p != pend) +- /* colored shorter than non-colored? */ ++ /* non-colored has more lines? */ ++ goto mismatched_output; ++ else if (colored_p == colored_pend) ++ /* last line has no matching colored one? */ + goto mismatched_output; + else + colored_p = colored_pend; + ## t/t3701-add-interactive.sh ## @@ t/t3701-add-interactive.sh: test_expect_success 'detect bogus diffFilter output' ' git reset --hard && echo content >test && - test_config interactive.diffFilter "sed 1d" && -+ test_config interactive.diffFilter "sed q" && ++ test_config interactive.diffFilter "sed 6d" && printf y >y && - force_color test_must_fail git add -p <y +- force_color test_must_fail git add -p <y ++ force_color test_must_fail git add -p <y >output 2>&1 && ++ grep "mismatched output" output ' + + test_expect_success 'handle very large filtered diff' ' 2: cbe833bd141 ! 2: cd1c5100506 add -p: gracefully ignore unparseable hunk headers in colored diffs @@ Metadata Author: Johannes Schindelin <Johannes.Schindelin@xxxxxx> ## Commit message ## - add -p: gracefully ignore unparseable hunk headers in colored diffs + add -p: gracefully handle unparseable hunk headers in colored diffs In https://lore.kernel.org/git/ecf6f5be-22ca-299f-a8f1-bda38e5ca246@xxxxxxxxx, @@ Commit message and therefore we cannot detect any part in that header that comes after the line range. - Let's punt for now and simply show nothing apart from the line range in - that case. + As proposed by Phillip Wood, let's take that for a clear indicator that + we should show the hunk headers verbatim. This is what the Perl version + of the interactive `add` command did, too. + + This commit is best viewed with `--color-moved --ignore-space-change`. [diff-so-fancy]: https://github.com/so-fancy/diff-so-fancy Reported-by: Philippe Blain <levraiphilippeblain@xxxxxxxxx> + Helped-by: Phillip Wood <phillip.wood@xxxxxxxxxxxxx> Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> ## add-patch.c ## +@@ add-patch.c: struct hunk_header { + * include the newline. + */ + size_t extra_start, extra_end, colored_extra_start, colored_extra_end; ++ unsigned suppress_colored_line_range:1; + }; + + struct hunk { @@ add-patch.c: static int parse_hunk_header(struct add_p_state *s, struct hunk *hunk) - eol = memchr(line, '\n', s->colored.len - hunk->colored_start); if (!eol) eol = s->colored.buf + s->colored.len; -- p = memmem(line, eol - line, "@@ -", 4); + p = memmem(line, eol - line, "@@ -", 4); - if (!p) - return error(_("could not parse colored hunk header '%.*s'"), - (int)(eol - line), line); @@ add-patch.c: static int parse_hunk_header(struct add_p_state *s, struct hunk *hu - if (!p) - return error(_("could not parse colored hunk header '%.*s'"), - (int)(eol - line), line); - hunk->colored_start = eol - s->colored.buf + (*eol == '\n'); -- header->colored_extra_start = p + 3 - s->colored.buf; -+ p = memmem(line, eol - line, "@@ -", 4); + if (p && (p = memmem(p + 4, eol - p - 4, " @@", 3))) + header->colored_extra_start = p + 3 - s->colored.buf; -+ else -+ /* could not parse colored hunk header, showing nothing */ ++ else { ++ /* could not parse colored hunk header, leave as-is */ + header->colored_extra_start = hunk->colored_start; ++ header->suppress_colored_line_range = 1; ++ } + hunk->colored_start = eol - s->colored.buf + (*eol == '\n'); +- header->colored_extra_start = p + 3 - s->colored.buf; header->colored_extra_end = hunk->colored_start; return 0; +@@ add-patch.c: static void render_hunk(struct add_p_state *s, struct hunk *hunk, + - header->colored_extra_start; + } + +- if (s->mode->is_reverse) +- old_offset -= delta; +- else +- new_offset += delta; +- +- strbuf_addf(out, "@@ -%lu", old_offset); +- if (header->old_count != 1) +- strbuf_addf(out, ",%lu", header->old_count); +- strbuf_addf(out, " +%lu", new_offset); +- if (header->new_count != 1) +- strbuf_addf(out, ",%lu", header->new_count); +- strbuf_addstr(out, " @@"); ++ if (!colored || !header->suppress_colored_line_range) { ++ if (s->mode->is_reverse) ++ old_offset -= delta; ++ else ++ new_offset += delta; ++ ++ strbuf_addf(out, "@@ -%lu", old_offset); ++ if (header->old_count != 1) ++ strbuf_addf(out, ",%lu", header->old_count); ++ strbuf_addf(out, " +%lu", new_offset); ++ if (header->new_count != 1) ++ strbuf_addf(out, ",%lu", header->new_count); ++ strbuf_addstr(out, " @@"); ++ } + + if (len) + strbuf_add(out, p, len); ## t/t3701-add-interactive.sh ## @@ t/t3701-add-interactive.sh: test_expect_success 'detect bogus diffFilter output' ' - force_color test_must_fail git add -p <y + grep "mismatched output" output ' +test_expect_success 'handle iffy colored hunk headers' ' @@ t/t3701-add-interactive.sh: test_expect_success 'detect bogus diffFilter output' + + echo content >test && + printf n >n && -+ force_color git -c interactive.diffFilter="sed s/@@/XX/g" \ -+ add -p <n ++ force_color git -c interactive.diffFilter="sed s/.*@@.*/XX/" \ ++ add -p >output 2>&1 <n && ++ grep "^[^@]*XX[^@]*$" output +' + test_expect_success 'handle very large filtered diff' ' 3: 7a9f0b107e6 < -: ----------- add -p: insert space in colored hunk header as needed 4: e3e3a178f98 < -: ----------- add -p: handle `diff-so-fancy`'s hunk headers better 5: cfa6914aee0 = 3: 116f0cf5cab add -p: ignore dirty submodules -- gitgitgadget
