From da8063522f7f797cf722f28979aefbe2a508f800 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Fri, 31 Jan 2020 04:57:49 -0500
Subject: diff: move diff.wsErrorHighlight to "basic" config

We parse diff.wsErrorHighlight in git_diff_ui_config(), meaning that it
doesn't take effect for plumbing commands, only for porcelains like
git-diff itself. This is mildly annoying as it means scripts like
add--interactive, which produce a user-visible diff with color, don't
respect the option.

We could teach that script to parse the config and pass it along as
--ws-error-highlight to the diff plumbing. But there's a simpler
solution.

It should be reasonably safe for plumbing to respect this option, as it
only kicks in when color is otherwise enabled. And anybody parsing
colorized output must already deal with the fact that color.diff.* may
change the exact output they see; those options have been part of
git_diff_basic_config() since its inception in 9a1805a872 (add a "basic"
diff config callback, 2008-01-04).

So we can just move it to the "basic" config, which fixes
add--interactive, along with any other script in the same boat, with a
very low risk of hurting any plumbing users.

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

diff --git a/diff.c b/diff.c
index 8e2914c..5e4471f 100644
--- a/diff.c
+++ b/diff.c
@@ -414,14 +414,6 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	if (!strcmp(var, "diff.wserrorhighlight")) {
-		int val = parse_ws_error_highlight(value);
-		if (val < 0)
-			return -1;
-		ws_error_highlight_default = val;
-		return 0;
-	}
-
 	if (git_color_config(var, value, cb) < 0)
 		return -1;
 
@@ -450,6 +442,14 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
 		return color_parse(value, diff_colors[slot]);
 	}
 
+	if (!strcmp(var, "diff.wserrorhighlight")) {
+		int val = parse_ws_error_highlight(value);
+		if (val < 0)
+			return -1;
+		ws_error_highlight_default = val;
+		return 0;
+	}
+
 	/* like GNU diff's --suppress-blank-empty option  */
 	if (!strcmp(var, "diff.suppressblankempty") ||
 			/* for backwards compatibility */
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index 12ee321..5337ccc 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -544,6 +544,19 @@ test_expect_success 'diffs can be colorized' '
 	grep "$(printf "\\033")" output
 '
 
+test_expect_success 'colorized diffs respect diff.wsErrorHighlight' '
+	git reset --hard &&
+
+	echo "old " >test &&
+	git add test &&
+	echo "new " >test &&
+
+	printf y >y &&
+	force_color git -c diff.wsErrorHighlight=all add -p >output.raw 2>&1 <y &&
+	test_decode_color <output.raw >output &&
+	grep "old<" output
+'
+
 test_expect_success 'diffFilter filters diff' '
 	git reset --hard &&
 
-- 
cgit v0.10.2-6-g49f6