[PATCH v2] log: if --decorate is not given, default to --decorate=auto

[Alex Henrie]

Signed-off-by: Alex Henrie <alexhenri...@gmail.com>
---
 builtin/log.c  |  9 ++++++++-
 t/t4202-log.sh | 10 +++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/builtin/log.c b/builtin/log.c
index 281af8c1e..d755a5960 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -52,6 +52,11 @@ struct line_opt_callback_data {
        struct string_list args;
 };
 
+static int auto_decoration_style(void)
+{
+       return (isatty(1) || pager_in_use()) ? DECORATE_SHORT_REFS : 0;
+}
+
 static int parse_decoration_style(const char *var, const char *value)
 {
        switch (git_config_maybe_bool(var, value)) {
@@ -67,7 +72,7 @@ static int parse_decoration_style(const char *var, const char 
*value)
        else if (!strcmp(value, "short"))
                return DECORATE_SHORT_REFS;
        else if (!strcmp(value, "auto"))
-               return (isatty(1) || pager_in_use()) ? DECORATE_SHORT_REFS : 0;
+               return auto_decoration_style();
        return -1;
 }
 
@@ -405,6 +410,8 @@ static int git_log_config(const char *var, const char 
*value, void *cb)
                if (decoration_style < 0)
                        decoration_style = 0; /* maybe warn? */
                return 0;
+       } else {
+               decoration_style = auto_decoration_style();
        }
        if (!strcmp(var, "log.showroot")) {
                default_show_root = git_config_bool(var, value);
diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index 48b55bfd2..f57799071 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -4,6 +4,7 @@ test_description='git log'
 
 . ./test-lib.sh
 . "$TEST_DIRECTORY/lib-gpg.sh"
+. "$TEST_DIRECTORY/lib-terminal.sh"
 
 test_expect_success setup '
 
@@ -520,7 +521,7 @@ test_expect_success 'log --graph with merge' '
 '
 
 test_expect_success 'log.decorate configuration' '
-       git log --oneline >expect.none &&
+       git log --oneline --no-decorate >expect.none &&
        git log --oneline --decorate >expect.short &&
        git log --oneline --decorate=full >expect.full &&
 
@@ -576,6 +577,13 @@ test_expect_success 'log.decorate configuration' '
 
 '
 
+test_expect_success TTY 'log output on a TTY' '
+       git log --oneline --decorate >expect.short &&
+
+       test_terminal git log --oneline >actual &&
+       test_cmp expect.short actual
+'
+
 test_expect_success 'reflog is expected format' '
        git log -g --abbrev-commit --pretty=oneline >expect &&
        git reflog >actual &&
-- 
2.12.0