Revert "color: check color.ui in git_default_config()"

This reverts commit 136c8c8b8fa39f1315713248473dececf20f8fe7.

That commit was trying to address a bug caused by 4c7f1819b3
(make color.ui default to 'auto', 2013-06-10), in which
plumbing like diff-tree defaulted to "auto" color, but did
not respect a "color.ui" directive to disable it.

But it also meant that we started respecting "color.ui" set
to "always". This was a known problem, but 4c7f1819b3 argued
that nobody ought to be doing that. However, that turned out
to be wrong, and we got a number of bug reports related to
"add -p" regressing in v2.14.2.

Let's revert 136c8c8b8, fixing the regression to "add -p".
This leaves the problem from 4c7f1819b3 unfixed, but:

  1. It's a pretty obscure problem in the first place. I
     only noticed it while working on the color code, and we
     haven't got a single bug report or complaint about it.

  2. We can make a more moderate fix on top by respecting
     "never" but not "always" for plumbing commands. This
     is just the minimal fix to go back to the working state
     we had before v2.14.2.

Note that this isn't a pure revert. We now have a test in
t3701 which shows off the "add -p" regression. This can be
flipped to success.

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

8 files changed, 17 insertions, 9 deletions

diff --git a/builtin/branch.c b/builtin/branch.c
index 16d391b407..1969c7116c 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -92,7 +92,7 @@ static int git_branch_config(const char *var, const char *value, void *cb)
 			return config_error_nonbool(var);
 		return color_parse(value, branch_colors[slot]);
 	}
-	return git_default_config(var, value, cb);
+	return git_color_default_config(var, value, cb);
 }
 
 static const char *branch_get_color(enum color_branch ix)
diff --git a/builtin/clean.c b/builtin/clean.c
index c1bafda5b6..057fc97fe4 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -125,7 +125,8 @@ static int git_clean_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	/* inspect the color.ui config variable and others */
+	return git_color_default_config(var, value, cb);
 }
 
 static const char *clean_get_color(enum color_clean ix)
diff --git a/builtin/grep.c b/builtin/grep.c
index 42ff87065a..7e79eb1a75 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -284,7 +284,7 @@ static int wait_all(void)
 static int grep_cmd_config(const char *var, const char *value, void *cb)
 {
 	int st = grep_config(var, value, cb);
-	if (git_default_config(var, value, cb) < 0)
+	if (git_color_default_config(var, value, cb) < 0)
 		st = -1;
 
 	if (!strcmp(var, "grep.threads")) {
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 28f245c8cc..7073a3eb97 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -554,7 +554,7 @@ static int git_show_branch_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_color_default_config(var, value, cb);
 }
 
 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
diff --git a/color.c b/color.c
index 7aa8b076f0..31b6207a00 100644
--- a/color.c
+++ b/color.c
@@ -361,6 +361,14 @@ int git_color_config(const char *var, const char *value, void *cb)
 	return 0;
 }
 
+int git_color_default_config(const char *var, const char *value, void *cb)
+{
+	if (git_color_config(var, value, cb) < 0)
+		return -1;
+
+	return git_default_config(var, value, cb);
+}
+
 void color_print_strbuf(FILE *fp, const char *color, const struct strbuf *sb)
 {
 	if (*color)
diff --git a/config.c b/config.c
index acebc85d81..231f9a750b 100644
--- a/config.c
+++ b/config.c
@@ -16,7 +16,6 @@
 #include "string-list.h"
 #include "utf8.h"
 #include "dir.h"
-#include "color.h"
 
 struct config_source {
 	struct config_source *prev;
@@ -1351,9 +1350,6 @@ int git_default_config(const char *var, const char *value, void *dummy)
 	if (starts_with(var, "advice."))
 		return git_default_advice_config(var, value);
 
-	if (git_color_config(var, value, dummy) < 0)
-		return -1;
-
 	if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 		pager_use_color = git_config_bool(var,value);
 		return 0;
diff --git a/diff.c b/diff.c
index 9c38258030..85e714f6c6 100644
--- a/diff.c
+++ b/diff.c
@@ -299,6 +299,9 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (git_color_config(var, value, cb) < 0)
+		return -1;
+
 	return git_diff_basic_config(var, value, cb);
 }
 
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index 87ffd4d43c..a49c12c79b 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -483,7 +483,7 @@ test_expect_success 'hunk-editing handles custom comment char' '
 	git diff --exit-code
 '
 
-test_expect_failure 'add -p works even with color.ui=always' '
+test_expect_success 'add -p works even with color.ui=always' '
 	git reset --hard &&
 	echo change >>file &&
 	test_config color.ui always &&