[PATCH] log: add log.follow config option

[David Turner <dturner@twopensource.com>]

Many users prefer to always use --follow with logs.  Rather than
aliasing the command, an option might be more convenient for some.

Signed-off-by: David Turner <dturner@twopensource.com>
---

Why not just alias log=log --follow?

At Twitter, we manage git config centrally, but we also allow users to
add their own aliases.  We would like to turn log.follow on globally,
while not messing up any aliases users already have for log.

Also, some users might have different log aliases for different
repositories, but want to manage --follow globally.

And in the future, we might want to make log --follow the default (it
is what I usually want), so it would be nice to provide a way for
users to turn that off globally from a config option.

 builtin/log.c                       |  7 +++++++
 t/t4206-log-follow-harder-copies.sh | 23 +++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/builtin/log.c b/builtin/log.c
index 8781049..11b8d82 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -31,6 +31,7 @@ static const char *default_date_mode = NULL;
 
 static int default_abbrev_commit;
 static int default_show_root = 1;
+static int default_follow = 0;
 static int decoration_style;
 static int decoration_given;
 static int use_mailmap_config;
@@ -102,6 +103,8 @@ static void cmd_log_init_defaults(struct rev_info *rev)
 {
 	if (fmt_pretty)
 		get_commit_format(fmt_pretty, rev);
+	if (default_follow)
+		DIFF_OPT_SET(&rev->diffopt, FOLLOW_RENAMES);
 	rev->verbose_header = 1;
 	DIFF_OPT_SET(&rev->diffopt, RECURSIVE);
 	rev->diffopt.stat_width = -1; /* use full terminal width */
@@ -390,6 +393,10 @@ static int git_log_config(const char *var, const char *value, void *cb)
 		default_show_root = git_config_bool(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "log.follow")) {
+		default_follow = git_config_bool(var, value);
+		return 0;
+	}
 	if (skip_prefix(var, "color.decorate.", &slot_name))
 		return parse_decorate_color_config(var, slot_name, value);
 	if (!strcmp(var, "log.mailmap")) {
diff --git a/t/t4206-log-follow-harder-copies.sh b/t/t4206-log-follow-harder-copies.sh
index ad29e65..6b2f3b9 100755
--- a/t/t4206-log-follow-harder-copies.sh
+++ b/t/t4206-log-follow-harder-copies.sh
@@ -53,4 +53,27 @@ test_expect_success \
     'validate the output.' \
     'compare_diff_patch current expected'
 
+test_expect_success \
+    'git config log.follow works like --follow' \
+    'test_config log.follow true &&
+     git log --name-status --pretty="format:%s"  path1 > current'
+
+test_expect_success \
+    'validate the output.' \
+    'compare_diff_patch current expected'
+
+test_expect_success \
+    'git config log.follow is overridden by --no-follow' \
+    'test_config log.follow true &&
+     git log --no-follow --name-status --pretty="format:%s"  path1 > current'
+
+cat >expected <<\EOF
+Copy path1 from path0
+A	path1
+EOF
+
+test_expect_success \
+    'validate the output.' \
+    'compare_diff_patch current expected'
+
 test_done
-- 
2.0.5.499.g01f6352.dirty-twtrsrc