@matheusbsbs / matheus-bagliano / commits / 75408ca949

diff-filter: be more careful when looking for negative bits

The `--diff-filter=<bits>` option allows to filter the diff by certain criteria, for example `R` to only show renamed files. It also supports negating a filter via a down-cased letter, i.e. `r` to show _everything but_ renamed files. However, the code is a bit overzealous when trying to figure out whether `git diff` should start with all diff-filters turned on because the user provided a lower-case letter: if the `--diff-filter` argument starts with an upper-case letter, we must not start with all bits turned on. Even worse, it is possible to specify the diff filters in multiple, separate options, e.g. `--diff-filter=AM [...] --diff-filter=m`. Let's accumulate the include/exclude filters independently, and only special-case the "only exclude filters were specified" case after parsing the options altogether. Note: The code replaced by this commit took pains to avoid setting any unused bits of `options->filter`. That was unnecessary, though, as all accesses happen via the `filter_bit_tst()` function using specific bits, and setting the unused bits has no effect. Therefore, we can simplify the code by using `~0` (or in this instance, `~<unwanted-bit>`). Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Jan 28, 2022 at 12:02 UTC 75408ca94980c125b3a800003c3e6b7cdcb27d44

3 files changed +21 -17

diff.c

+7 -16

@@ -4720,6 +4720,12 @@ void diff_setup_done(struct diff_options *options)

4720 if (!options->use_color || external_diff())

4721 options->color_moved = 0;

4722

4723 + if (options->filter_not) {

4724 + if (!options->filter)

4725 + options->filter = ~filter_bit[DIFF_STATUS_FILTER_AON];

4726 + options->filter &= ~options->filter_not;

4727 + }

4728 +

4729 FREE_AND_NULL(options->parseopts);

4730 }

4731

@@ -4820,21 +4826,6 @@ static int diff_opt_diff_filter(const struct option *option,

4826 BUG_ON_OPT_NEG(unset);

4827 prepare_filter_bits();

4828

4823 - /*

4824 - * If there is a negation e.g. 'd' in the input, and we haven't

4825 - * initialized the filter field with another --diff-filter, start

4826 - * from full set of bits, except for AON.

4827 - */

4828 - if (!opt->filter) {

4829 - for (i = 0; (optch = optarg[i]) != '\0'; i++) {

4830 - if (optch < 'a' || 'z' < optch)

4831 - continue;

4832 - opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;

4833 - opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];

4834 - break;

4835 - }

4836 - }

4837 -

4829 for (i = 0; (optch = optarg[i]) != '\0'; i++) {

4830 unsigned int bit;

4831 int negate;

@@ -4851,7 +4842,7 @@ static int diff_opt_diff_filter(const struct option *option,

4842 return error(_("unknown change class '%c' in --diff-filter=%s"),

4843 optarg[i], optarg);

4844 if (negate)

4854 - opt->filter &= ~bit;

4845 + opt->filter_not |= bit;

4846 else

4847 opt->filter |= bit;

4848 }

diff.h

+1 -1

@@ -283,7 +283,7 @@ struct diff_options {

283 struct diff_flags flags;

284

285 /* diff-filter bits */

286 - unsigned int filter;

286 + unsigned int filter, filter_not;

287

288 int use_color;

289

t/t4202-log.sh

+13

@@ -142,6 +142,19 @@ test_expect_success 'diff-filter=R' '

142

143 '

144

145 +test_expect_success 'multiple --diff-filter bits' '

146 +

147 + git log -M --pretty="format:%s" --diff-filter=R HEAD >expect &&

148 + git log -M --pretty="format:%s" --diff-filter=Ra HEAD >actual &&

149 + test_cmp expect actual &&

150 + git log -M --pretty="format:%s" --diff-filter=aR HEAD >actual &&

151 + test_cmp expect actual &&

152 + git log -M --pretty="format:%s" \

153 + --diff-filter=a --diff-filter=R HEAD >actual &&

154 + test_cmp expect actual

155 +

156 +'

157 +

158 test_expect_success 'diff-filter=C' '

159

160 git log -C -C --pretty="format:%s" --diff-filter=C HEAD >actual &&