log --format: teach %C(auto,black) to respect color config

Traditionally, %C(color attr) always emitted the ANSI color
sequence; it was up to the scripts that wanted to conditionally
color their output to omit %C(...) specifier when they do not want
colors.

Optionally allow "auto," to be prefixed to the color, so that the
output is colored iff we would color regular "log" output
(e.g., taking into account color.* and --color command line
options).

Tests and pretty_context bits by Jeff King <peff@peff.net>.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index d9eddedc72a5e6362d68df1b126b76804b9676e1..105f18a6f9fd9f4a5a388cb3ec8a0e6a99f7abe3 100644 (file)
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -144,7 +144,11 @@ The placeholders are:
 - '%Cgreen': switch color to green
 - '%Cblue': switch color to blue
 - '%Creset': reset color
-- '%C(...)': color specification, as described in color.branch.* config option
+- '%C(...)': color specification, as described in color.branch.* config option;
+  adding `auto,` at the beginning will emit color only when colors are
+  enabled for log output (by `color.diff`, `color.ui`, or `--color`, and
+  respecting the `auto` settings of the former if we are going to a
+  terminal)
 - '%m': left, right or boundary mark
 - '%n': newline
 - '%%': a raw '%'

diff --git a/commit.h b/commit.h
index 9f2131318d4c43fdaaca40e45e45e7d1af61cdfe..73fd399b09ea9a60965d318e5d282c932a50f44e 100644 (file)
--- a/commit.h
+++ b/commit.h
@@ -89,6 +89,7 @@ struct pretty_print_context {
        int show_notes;
        struct reflog_walk_info *reflog_info;
        const char *output_encoding;
+       int color;
 };
 
 struct userformat_want {

diff --git a/log-tree.c b/log-tree.c
index c894930c1863bfcf33a01b2d98c48478aa874186..7185bd65f2540d8c2c929d4f078e280f4d869712 100644 (file)
--- a/log-tree.c
+++ b/log-tree.c
@@ -660,6 +660,7 @@ void show_log(struct rev_info *opt)
        ctx.preserve_subject = opt->preserve_subject;
        ctx.reflog_info = opt->reflog_info;
        ctx.fmt = opt->commit_format;
+       ctx.color = opt->diffopt.use_color;
        pretty_print_commit(&ctx, commit, &msgbuf);
 
        if (opt->add_signoff)

diff --git a/pretty.c b/pretty.c
index dba682828c2e005b71c0ccbb325fb666915984bc..63350af6145248aaaafc131ebbdb4e8a91ae7eb0 100644 (file)
--- a/pretty.c
+++ b/pretty.c
@@ -960,12 +960,19 @@ static size_t format_commit_one(struct strbuf *sb, const char *placeholder,
        switch (placeholder[0]) {
        case 'C':
                if (placeholder[1] == '(') {
-                       const char *end = strchr(placeholder + 2, ')');
+                       const char *begin = placeholder + 2;
+                       const char *end = strchr(begin, ')');
                        char color[COLOR_MAXLEN];
+
                        if (!end)
                                return 0;
-                       color_parse_mem(placeholder + 2,
-                                       end - (placeholder + 2),
+                       if (!memcmp(begin, "auto,", 5)) {
+                               if (!want_color(c->pretty_ctx->color))
+                                       return end - placeholder + 1;
+                               begin += 5;
+                       }
+                       color_parse_mem(begin,
+                                       end - begin,
                                        "--pretty format", color);
                        strbuf_addstr(sb, color);
                        return end - placeholder + 1;

diff --git a/t/t6006-rev-list-format.sh b/t/t6006-rev-list-format.sh
index c0c62c9da01973a754e83a0f6397caf44726f58d..3fc3b74c8efa4e5092e36e6a6fbd2a15bc862d77 100755 (executable)
--- a/t/t6006-rev-list-format.sh
+++ b/t/t6006-rev-list-format.sh
@@ -3,6 +3,7 @@
 test_description='git rev-list --pretty=format test'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-terminal.sh
 
 test_tick
 test_expect_success 'setup' '
@@ -19,6 +20,18 @@ test_format () {
        "
 }
 
+# Feed to --format to provide predictable colored sequences.
+AUTO_COLOR='%C(auto,red)foo%C(auto,reset)'
+has_color () {
+       printf '\033[31mfoo\033[m\n' >expect &&
+       test_cmp expect "$1"
+}
+
+has_no_color () {
+       echo foo >expect &&
+       test_cmp expect "$1"
+}
+
 test_format percent %%h <<'EOF'
 commit 131a310eb913d107dd3c09a65d1651175898735d
 %h
@@ -124,6 +137,48 @@ commit 86c75cfd708a0e5868dc876ed5b8bb66c80b4873
 \e[1;31;43mfoo\e[m
 EOF
 
+test_expect_success '%C(auto) does not enable color by default' '
+       git log --format=$AUTO_COLOR -1 >actual &&
+       has_no_color actual
+'
+
+test_expect_success '%C(auto) enables colors for color.diff' '
+       git -c color.diff=always log --format=$AUTO_COLOR -1 >actual &&
+       has_color actual
+'
+
+test_expect_success '%C(auto) enables colors for color.ui' '
+       git -c color.ui=always log --format=$AUTO_COLOR -1 >actual &&
+       has_color actual
+'
+
+test_expect_success '%C(auto) respects --color' '
+       git log --format=$AUTO_COLOR -1 --color >actual &&
+       has_color actual
+'
+
+test_expect_success '%C(auto) respects --no-color' '
+       git -c color.ui=always log --format=$AUTO_COLOR -1 --no-color >actual &&
+       has_no_color actual
+'
+
+test_expect_success TTY '%C(auto) respects --color=auto (stdout is tty)' '
+       (
+               TERM=vt100 && export TERM &&
+               test_terminal \
+                       git log --format=$AUTO_COLOR -1 --color=auto >actual &&
+               has_color actual
+       )
+'
+
+test_expect_success '%C(auto) respects --color=auto (stdout not tty)' '
+       (
+               TERM=vt100 && export TERM &&
+               git log --format=$AUTO_COLOR -1 --color=auto >actual &&
+               has_no_color actual
+       )
+'
+
 cat >commit-msg <<'EOF'
 Test printing of complex bodies