Add color.ui variable which globally enables colorization if set

Signed-off-by: Matthias Kestenholz <mk@spinlock.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -489,6 +489,13 @@ color.status.<slot>::
 commit.template::
 	Specify a file to use as the template for new commit messages.
 
+color.ui::
+	When set to `always`, always use colors in all git commands which
+	are capable of colored output. When false (or `never`), never. When
+	set to `true` or `auto`, use colors only when the output is to the
+	terminal. When more specific variables of color.* are set, they always
+	take precedence over this setting. Defaults to false.
+
 diff.autorefreshindex::
 	When using `git diff` to compare with work tree
 	files, do not consider stat-only change as changed.

builtin-branch.c

@@ -31,7 +31,7 @@ static unsigned char head_sha1[20];
 
 static int branch_track = 1;
 
-static int branch_use_color;
+static int branch_use_color = -1;
 static char branch_colors[][COLOR_MAXLEN] = {
 	"\033[m",	/* reset */
 	"",		/* PLAIN (normal) */
@@ -79,12 +79,12 @@ static int git_branch_config(const char *var, const char *value)
 		branch_track = git_config_bool(var, value);
 		return 0;
 	}
-	return git_default_config(var, value);
+	return git_color_default_config(var, value);
 }
 
 static const char *branch_get_color(enum color_branch ix)
 {
-	if (branch_use_color)
+	if (branch_use_color > 0)
 		return branch_colors[ix];
 	return "";
 }
@@ -588,6 +588,10 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 	};
 
 	git_config(git_branch_config);
+
+	if (branch_use_color == -1)
+		branch_use_color = git_use_color_default;
+
 	track = branch_track;
 	argc = parse_options(argc, argv, options, builtin_branch_usage, 0);
 	if (!!delete + !!rename + !!force_create > 1)

builtin-commit.c

@@ -7,6 +7,7 @@
 
 #include "cache.h"
 #include "cache-tree.h"
+#include "color.h"
 #include "dir.h"
 #include "builtin.h"
 #include "diff.h"
@@ -771,6 +772,9 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 
 	git_config(git_status_config);
 
+	if (wt_status_use_color == -1)
+		wt_status_use_color = git_use_color_default;
+
 	argc = parse_and_validate_options(argc, argv, builtin_status_usage);
 
 	index_file = prepare_index(argc, argv, prefix);

builtin-diff.c

@@ -4,6 +4,7 @@
  * Copyright (c) 2006 Junio C Hamano
  */
 #include "cache.h"
+#include "color.h"
 #include "commit.h"
 #include "blob.h"
 #include "tag.h"
@@ -229,6 +230,10 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 
 	prefix = setup_git_directory_gently(&nongit);
 	git_config(git_diff_ui_config);
+
+	if (diff_use_color_default == -1)
+		diff_use_color_default = git_use_color_default;
+
 	init_revisions(&rev, prefix);
 	rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 

builtin-log.c

@@ -5,6 +5,7 @@
  *		 2006 Junio Hamano
  */
 #include "cache.h"
+#include "color.h"
 #include "commit.h"
 #include "diff.h"
 #include "revision.h"
@@ -235,6 +236,10 @@ int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 	struct rev_info rev;
 
 	git_config(git_log_config);
+
+	if (diff_use_color_default == -1)
+		diff_use_color_default = git_use_color_default;
+
 	init_revisions(&rev, prefix);
 	rev.diff = 1;
 	rev.simplify_history = 0;
@@ -307,6 +312,10 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 	int i, count, ret = 0;
 
 	git_config(git_log_config);
+
+	if (diff_use_color_default == -1)
+		diff_use_color_default = git_use_color_default;
+
 	init_revisions(&rev, prefix);
 	rev.diff = 1;
 	rev.combine_merges = 1;
@@ -367,6 +376,10 @@ int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 	struct rev_info rev;
 
 	git_config(git_log_config);
+
+	if (diff_use_color_default == -1)
+		diff_use_color_default = git_use_color_default;
+
 	init_revisions(&rev, prefix);
 	init_reflog_walk(&rev.reflog_info);
 	rev.abbrev_commit = 1;
@@ -395,6 +408,10 @@ int cmd_log(int argc, const char **argv, const char *prefix)
 	struct rev_info rev;
 
 	git_config(git_log_config);
+
+	if (diff_use_color_default == -1)
+		diff_use_color_default = git_use_color_default;
+
 	init_revisions(&rev, prefix);
 	rev.always_show_header = 1;
 	cmd_log_init(argc, argv, prefix, &rev);

color.c

@@ -3,6 +3,8 @@
 
 #define COLOR_RESET "\033[m"
 
+int git_use_color_default = 0;
+
 static int parse_color(const char *name, int len)
 {
 	static const char * const color_names[] = {
@@ -143,6 +145,16 @@ int git_config_colorbool(const char *var, const char *value, int stdout_is_tty)
 	return 0;
 }
 
+int git_color_default_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "color.ui")) {
+		git_use_color_default = git_config_colorbool(var, value, -1);
+		return 0;
+	}
+
+	return git_default_config(var, value);
+}
+
 static int color_vfprintf(FILE *fp, const char *color, const char *fmt,
 		va_list args, const char *trail)
 {

color.h

@@ -4,6 +4,17 @@
 /* "\033[1;38;5;2xx;48;5;2xxm\0" is 23 bytes */
 #define COLOR_MAXLEN 24
 
+/*
+ * This variable stores the value of color.ui
+ */
+extern int git_use_color_default;
+
+
+/*
+ * Use this instead of git_default_config if you need the value of color.ui.
+ */
+int git_color_default_config(const char *var, const char *value);
+
 int git_config_colorbool(const char *var, const char *value, int stdout_is_tty);
 void color_parse(const char *var, const char *value, char *dst);
 int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);

diff.c

@@ -20,7 +20,7 @@
 
 static int diff_detect_rename_default;
 static int diff_rename_limit_default = 100;
-static int diff_use_color_default;
+int diff_use_color_default = -1;
 static const char *external_diff_cmd_cfg;
 int diff_auto_refresh_index = 1;
 
@@ -191,7 +191,7 @@ int git_diff_basic_config(const char *var, const char *value)
 		}
 	}
 
-	return git_default_config(var, value);
+	return git_color_default_config(var, value);
 }
 
 static char *quote_two(const char *one, const char *two)
@@ -2055,7 +2055,7 @@ void diff_setup(struct diff_options *options)
 
 	options->change = diff_change;
 	options->add_remove = diff_addremove;
-	if (diff_use_color_default)
+	if (diff_use_color_default > 0)
 		DIFF_OPT_SET(options, COLOR_DIFF);
 	else
 		DIFF_OPT_CLR(options, COLOR_DIFF);

diff.h

@@ -174,6 +174,7 @@ extern void diff_unmerge(struct diff_options *,
 
 extern int git_diff_basic_config(const char *var, const char *value);
 extern int git_diff_ui_config(const char *var, const char *value);
+extern int diff_use_color_default;
 extern void diff_setup(struct diff_options *);
 extern int diff_opt_parse(struct diff_options *, const char **, int);
 extern int diff_setup_done(struct diff_options *);

wt-status.c

@@ -9,7 +9,7 @@
 #include "diffcore.h"
 
 int wt_status_relative_paths = 1;
-int wt_status_use_color = 0;
+int wt_status_use_color = -1;
 static char wt_status_colors[][COLOR_MAXLEN] = {
 	"",         /* WT_STATUS_HEADER: normal */
 	"\033[32m", /* WT_STATUS_UPDATED: green */
@@ -40,7 +40,7 @@ static int parse_status_slot(const char *var, int offset)
 
 static const char* color(int slot)
 {
-	return wt_status_use_color ? wt_status_colors[slot] : "";
+	return wt_status_use_color > 0 ? wt_status_colors[slot] : "";
 }
 
 void wt_status_prepare(struct wt_status *s)
@@ -401,5 +401,5 @@ int git_status_config(const char *k, const char *v)
 		wt_status_relative_paths = git_config_bool(k, v);
 		return 0;
 	}
-	return git_default_config(k, v);
+	return git_color_default_config(k, v);
 }