[PATCH 2/2] Highlight keywords in remote sideband output.

[Han-Wen Nienhuys <hanwen@google.com>]

The highlighting is done on the client-side. Supported keywords are
"error", "warning", "hint" and "success".

The colorization is controlled with the config setting "color.remote".

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Change-Id: I090412a1288bc2caef0916447e28c2d0199da47d
---
 sideband.c                          | 79 +++++++++++++++++++++++++----
 t/t5409-colorize-remote-messages.sh | 34 +++++++++++++
 2 files changed, 104 insertions(+), 9 deletions(-)
 create mode 100644 t/t5409-colorize-remote-messages.sh

diff --git a/sideband.c b/sideband.c
index 325bf0e97..15213a7c1 100644
--- a/sideband.c
+++ b/sideband.c
@@ -1,6 +1,63 @@
 #include "cache.h"
 #include "pkt-line.h"
 #include "sideband.h"
+#include "color.h"
+
+static int sideband_use_color = -1;
+
+/*
+ * Optionally highlight some keywords in remote output if they appear at the
+ * start of the line.
+ */
+void maybe_colorize_sideband(struct strbuf *dest, const char *src, int n)
+{
+	if (sideband_use_color < 0) {
+		const char *key = "color.remote";
+		char *value = NULL;
+		if (!git_config_get_string(key, &value))
+			sideband_use_color = git_config_colorbool(key, value);
+	}
+
+	int want_color = want_color_stderr(sideband_use_color);
+	int i;
+
+	if (!want_color) {
+		strbuf_add(dest, src, n);
+		return;
+	}
+
+	struct kwtable {
+		const char *keyword;
+		const char *color;
+	} keywords[] = {
+		{"hint", GIT_COLOR_YELLOW},
+		{"warning", GIT_COLOR_BOLD_YELLOW},
+		{"success", GIT_COLOR_BOLD_GREEN},
+		{"error", GIT_COLOR_BOLD_RED},
+	};
+
+	while (isspace(*src)) {
+		strbuf_addch(dest, *src);
+		src++;
+		n--;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(keywords); i++) {
+		struct kwtable* p = keywords + i;
+		int len = strlen(p->keyword);
+		if (!strncasecmp(p->keyword, src, len) && !isalnum(src[len])) {
+			strbuf_addstr(dest, p->color);
+			strbuf_add(dest, src, len);
+			strbuf_addstr(dest, GIT_COLOR_RESET);
+			n -= len;
+			src += len;
+			break;
+		}
+	}
+
+	strbuf_add(dest, src, n);
+}
+
 
 /*
  * Receive multiplexed output stream over git native protocol.
@@ -48,8 +105,10 @@ int recv_sideband(const char *me, int in_stream, int out)
 		len--;
 		switch (band) {
 		case 3:
-			strbuf_addf(&outbuf, "%s%s%s", outbuf.len ? "\n" : "",
-				    DISPLAY_PREFIX, buf + 1);
+			strbuf_addf(&outbuf, "%s%s", outbuf.len ? "\n" : "",
+				    DISPLAY_PREFIX);
+			maybe_colorize_sideband(&outbuf, buf + 1, len);
+
 			retval = SIDEBAND_REMOTE_ERROR;
 			break;
 		case 2:
@@ -69,20 +128,22 @@ int recv_sideband(const char *me, int in_stream, int out)
 				if (!outbuf.len)
 					strbuf_addstr(&outbuf, DISPLAY_PREFIX);
 				if (linelen > 0) {
-					strbuf_addf(&outbuf, "%.*s%s%c",
-						    linelen, b, suffix, *brk);
-				} else {
-					strbuf_addch(&outbuf, *brk);
+					maybe_colorize_sideband(&outbuf, b, linelen);
+					strbuf_addstr(&outbuf, suffix);
 				}
+
+				strbuf_addch(&outbuf, *brk);
 				xwrite(2, outbuf.buf, outbuf.len);
 				strbuf_reset(&outbuf);
 
 				b = brk + 1;
 			}
 
-			if (*b)
-				strbuf_addf(&outbuf, "%s%s", outbuf.len ?
-					    "" : DISPLAY_PREFIX, b);
+			if (*b) {
+				strbuf_addstr(&outbuf, outbuf.len ?
+					    "" : DISPLAY_PREFIX);
+				maybe_colorize_sideband(&outbuf, b, strlen(b));
+			}
 			break;
 		case 1:
 			write_or_die(out, buf + 1, len);
diff --git a/t/t5409-colorize-remote-messages.sh b/t/t5409-colorize-remote-messages.sh
new file mode 100644
index 000000000..1620cffbe
--- /dev/null
+++ b/t/t5409-colorize-remote-messages.sh
@@ -0,0 +1,34 @@
+#!/bin/sh
+
+test_description='remote messages are colorized on the client'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	mkdir .git/hooks &&
+        cat << EOF > .git/hooks/update &&
+#!/bin/sh
+echo error: error
+echo hint: hint
+echo success: success
+echo warning: warning
+exit 0
+EOF
+	chmod +x .git/hooks/update &&
+	echo 1 >file &&
+	git add file &&
+	git commit -m 1 &&
+        git clone . child &&
+        cd child &&
+        echo 2 > file &&
+        git commit -a -m 2
+'
+
+test_expect_success 'push' 'git -c color.remote push origin HEAD:refs/heads/newbranch 2>output &&
+  test_decode_color < output > decoded &&
+  test_i18ngrep "<BOLD;RED>error<RESET>:" decoded &&
+  test_i18ngrep "<YELLOW>hint<RESET>:" decoded &&
+  test_i18ngrep "<BOLD;GREEN>success<RESET>:" decoded &&
+  test_i18ngrep "<BOLD;YELLOW>warning<RESET>:" decoded'
+
+test_done
-- 
2.18.0.345.g5c9ce644c3-goog