1 files changed, 239 insertions, 0 deletions
diff --git a/third_party/git/sideband.c b/third_party/git/sideband.c
new file mode 100644
index 000000000000..ef851113c44e
--- /dev/null
+++ b/third_party/git/sideband.c
@@ -0,0 +1,239 @@
+#include "cache.h"
+#include "color.h"
+#include "config.h"
+#include "sideband.h"
+#include "help.h"
+
+struct keyword_entry {
+	/*
+	 * We use keyword as config key so it should be a single alphanumeric word.
+	 */
+	const char *keyword;
+	char color[COLOR_MAXLEN];
+};
+
+static struct keyword_entry keywords[] = {
+	{ "hint",	GIT_COLOR_YELLOW },
+	{ "warning",	GIT_COLOR_BOLD_YELLOW },
+	{ "success",	GIT_COLOR_BOLD_GREEN },
+	{ "error",	GIT_COLOR_BOLD_RED },
+};
+
+/* Returns a color setting (GIT_COLOR_NEVER, etc). */
+static int use_sideband_colors(void)
+{
+	static int use_sideband_colors_cached = -1;
+
+	const char *key = "color.remote";
+	struct strbuf sb = STRBUF_INIT;
+	char *value;
+	int i;
+
+	if (use_sideband_colors_cached >= 0)
+		return use_sideband_colors_cached;
+
+	if (!git_config_get_string(key, &value)) {
+		use_sideband_colors_cached = git_config_colorbool(key, value);
+	} else if (!git_config_get_string("color.ui", &value)) {
+		use_sideband_colors_cached = git_config_colorbool("color.ui", value);
+	} else {
+		use_sideband_colors_cached = GIT_COLOR_AUTO;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(keywords); i++) {
+		strbuf_reset(&sb);
+		strbuf_addf(&sb, "%s.%s", key, keywords[i].keyword);
+		if (git_config_get_string(sb.buf, &value))
+			continue;
+		if (color_parse(value, keywords[i].color))
+			continue;
+	}
+	strbuf_release(&sb);
+	return use_sideband_colors_cached;
+}
+
+void list_config_color_sideband_slots(struct string_list *list, const char *prefix)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(keywords); i++)
+		list_config_item(list, prefix, keywords[i].keyword);
+}
+
+/*
+ * Optionally highlight one keyword in remote output if it appears at the start
+ * of the line. This should be called for a single line only, which is
+ * passed as the first N characters of the SRC array.
+ *
+ * NEEDSWORK: use "size_t n" instead for clarity.
+ */
+static void maybe_colorize_sideband(struct strbuf *dest, const char *src, int n)
+{
+	int i;
+
+	if (!want_color_stderr(use_sideband_colors())) {
+		strbuf_add(dest, src, n);
+		return;
+	}
+
+	while (0 < n && isspace(*src)) {
+		strbuf_addch(dest, *src);
+		src++;
+		n--;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(keywords); i++) {
+		struct keyword_entry *p = keywords + i;
+		int len = strlen(p->keyword);
+
+		if (n < len)
+			continue;
+		/*
+		 * Match case insensitively, so we colorize output from existing
+		 * servers regardless of the case that they use for their
+		 * messages. We only highlight the word precisely, so
+		 * "successful" stays uncolored.
+		 */
+		if (!strncasecmp(p->keyword, src, len) &&
+		    (len == n || !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);
+}
+
+
+#define DISPLAY_PREFIX "remote: "
+
+#define ANSI_SUFFIX "\033[K"
+#define DUMB_SUFFIX "        "
+
+int demultiplex_sideband(const char *me, char *buf, int len,
+			 int die_on_error,
+			 struct strbuf *scratch,
+			 enum sideband_type *sideband_type)
+{
+	static const char *suffix;
+	const char *b, *brk;
+	int band;
+
+	if (!suffix) {
+		if (isatty(2) && !is_terminal_dumb())
+			suffix = ANSI_SUFFIX;
+		else
+			suffix = DUMB_SUFFIX;
+	}
+
+	if (len == 0) {
+		*sideband_type = SIDEBAND_FLUSH;
+		goto cleanup;
+	}
+	if (len < 1) {
+		strbuf_addf(scratch,
+			    "%s%s: protocol error: no band designator",
+			    scratch->len ? "\n" : "", me);
+		*sideband_type = SIDEBAND_PROTOCOL_ERROR;
+		goto cleanup;
+	}
+	band = buf[0] & 0xff;
+	buf[len] = '\0';
+	len--;
+	switch (band) {
+	case 3:
+		if (die_on_error)
+			die("remote error: %s", buf + 1);
+		strbuf_addf(scratch, "%s%s", scratch->len ? "\n" : "",
+			    DISPLAY_PREFIX);
+		maybe_colorize_sideband(scratch, buf + 1, len);
+
+		*sideband_type = SIDEBAND_REMOTE_ERROR;
+		break;
+	case 2:
+		b = buf + 1;
+
+		/*
+		 * Append a suffix to each nonempty line to clear the
+		 * end of the screen line.
+		 *
+		 * The output is accumulated in a buffer and
+		 * each line is printed to stderr using
+		 * write(2) to ensure inter-process atomicity.
+		 */
+		while ((brk = strpbrk(b, "\n\r"))) {
+			int linelen = brk - b;
+
+			if (!scratch->len)
+				strbuf_addstr(scratch, DISPLAY_PREFIX);
+			if (linelen > 0) {
+				maybe_colorize_sideband(scratch, b, linelen);
+				strbuf_addstr(scratch, suffix);
+			}
+
+			strbuf_addch(scratch, *brk);
+			xwrite(2, scratch->buf, scratch->len);
+			strbuf_reset(scratch);
+
+			b = brk + 1;
+		}
+
+		if (*b) {
+			strbuf_addstr(scratch, scratch->len ?
+				    "" : DISPLAY_PREFIX);
+			maybe_colorize_sideband(scratch, b, strlen(b));
+		}
+		return 0;
+	case 1:
+		*sideband_type = SIDEBAND_PRIMARY;
+		break;
+	default:
+		strbuf_addf(scratch, "%s%s: protocol error: bad band #%d",
+			    scratch->len ? "\n" : "", me, band);
+		*sideband_type = SIDEBAND_PROTOCOL_ERROR;
+		break;
+	}
+
+cleanup:
+	if (die_on_error && *sideband_type == SIDEBAND_PROTOCOL_ERROR)
+		die("%s", scratch->buf);
+	if (scratch->len) {
+		strbuf_addch(scratch, '\n');
+		xwrite(2, scratch->buf, scratch->len);
+	}
+	strbuf_release(scratch);
+	return 1;
+}
+
+/*
+ * fd is connected to the remote side; send the sideband data
+ * over multiplexed packet stream.
+ */
+void send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
+{
+	const char *p = data;
+
+	while (sz) {
+		unsigned n;
+		char hdr[5];
+
+		n = sz;
+		if (packet_max - 5 < n)
+			n = packet_max - 5;
+		if (0 <= band) {
+			xsnprintf(hdr, sizeof(hdr), "%04x", n + 5);
+			hdr[4] = band;
+			write_or_die(fd, hdr, 5);
+		} else {
+			xsnprintf(hdr, sizeof(hdr), "%04x", n + 4);
+			write_or_die(fd, hdr, 4);
+		}
+		write_or_die(fd, p, n);
+		p += n;
+		sz -= n;
+	}
+}