merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 48 insertions, 31 deletions

diff --git a/third_party/git/mailinfo.c b/third_party/git/mailinfo.c
index b395adbdf2..5681d9130d 100644
--- a/third_party/git/mailinfo.c
+++ b/third_party/git/mailinfo.c
@@ -19,8 +19,7 @@ static void cleanup_space(struct strbuf *sb)
 static void get_sane_name(struct strbuf *out, struct strbuf *name, struct strbuf *email)
 {
 	struct strbuf *src = name;
-	if (name->len < 3 || 60 < name->len || strchr(name->buf, '@') ||
-		strchr(name->buf, '<') || strchr(name->buf, '>'))
+	if (name->len < 3 || 60 < name->len || strpbrk(name->buf, "@<>"))
 		src = email;
 	else if (name == out)
 		return;
@@ -254,7 +253,7 @@ static void handle_content_type(struct mailinfo *mi, struct strbuf *line)
 	mi->delsp = has_attr_value(line->buf, "delsp=", "yes");
 
 	if (slurp_attr(line->buf, "boundary=", boundary)) {
-		strbuf_insert(boundary, 0, "--", 2);
+		strbuf_insertstr(boundary, 0, "--");
 		if (++mi->content_top >= &mi->content[MAX_BOUNDARIES]) {
 			error("Too many boundaries to handle");
 			mi->input_error = -1;
@@ -346,11 +345,17 @@ static const char *header[MAX_HDR_PARSED] = {
 	"From","Subject","Date",
 };
 
-static inline int cmp_header(const struct strbuf *line, const char *hdr)
+static inline int skip_header(const struct strbuf *line, const char *hdr,
+			      const char **outval)
 {
-	int len = strlen(hdr);
-	return !strncasecmp(line->buf, hdr, len) && line->len > len &&
-			line->buf[len] == ':' && isspace(line->buf[len + 1]);
+	const char *val;
+	if (!skip_iprefix(line->buf, hdr, &val) ||
+	    *val++ != ':')
+		return 0;
+	while (isspace(*val))
+		val++;
+	*outval = val;
+	return 1;
 }
 
 static int is_format_patch_separator(const char *line, int len)
@@ -442,19 +447,21 @@ static int convert_to_utf8(struct mailinfo *mi,
 			   struct strbuf *line, const char *charset)
 {
 	char *out;
+	size_t out_len;
 
 	if (!mi->metainfo_charset || !charset || !*charset)
 		return 0;
 
 	if (same_encoding(mi->metainfo_charset, charset))
 		return 0;
-	out = reencode_string(line->buf, mi->metainfo_charset, charset);
+	out = reencode_string_len(line->buf, line->len,
+				  mi->metainfo_charset, charset, &out_len);
 	if (!out) {
 		mi->input_error = -1;
 		return error("cannot convert from %s to %s",
 			     charset, mi->metainfo_charset);
 	}
-	strbuf_attach(line, out, strlen(out), strlen(out));
+	strbuf_attach(line, out, out_len, out_len);
 	return 0;
 }
 
@@ -543,22 +550,36 @@ release_return:
 		mi->input_error = -1;
 }
 
+/*
+ * Returns true if "line" contains a header matching "hdr", in which case "val"
+ * will contain the value of the header with any RFC2047 B and Q encoding
+ * unwrapped, and optionally normalize the meta information to utf8.
+ */
+static int parse_header(const struct strbuf *line,
+			const char *hdr,
+			struct mailinfo *mi,
+			struct strbuf *val)
+{
+	const char *val_str;
+
+	if (!skip_header(line, hdr, &val_str))
+		return 0;
+	strbuf_addstr(val, val_str);
+	decode_header(mi, val);
+	return 1;
+}
+
 static int check_header(struct mailinfo *mi,
 			const struct strbuf *line,
 			struct strbuf *hdr_data[], int overwrite)
 {
-	int i, ret = 0, len;
+	int i, ret = 0;
 	struct strbuf sb = STRBUF_INIT;
 
 	/* search for the interesting parts */
 	for (i = 0; header[i]; i++) {
-		int len = strlen(header[i]);
-		if ((!hdr_data[i] || overwrite) && cmp_header(line, header[i])) {
-			/* Unwrap inline B and Q encoding, and optionally
-			 * normalize the meta information to utf8.
-			 */
-			strbuf_add(&sb, line->buf + len + 2, line->len - len - 2);
-			decode_header(mi, &sb);
+		if ((!hdr_data[i] || overwrite) &&
+		    parse_header(line, header[i], mi, &sb)) {
 			handle_header(&hdr_data[i], &sb);
 			ret = 1;
 			goto check_header_out;
@@ -566,27 +587,17 @@ static int check_header(struct mailinfo *mi,
 	}
 
 	/* Content stuff */
-	if (cmp_header(line, "Content-Type")) {
-		len = strlen("Content-Type: ");
-		strbuf_add(&sb, line->buf + len, line->len - len);
-		decode_header(mi, &sb);
-		strbuf_insert(&sb, 0, "Content-Type: ", len);
+	if (parse_header(line, "Content-Type", mi, &sb)) {
 		handle_content_type(mi, &sb);
 		ret = 1;
 		goto check_header_out;
 	}
-	if (cmp_header(line, "Content-Transfer-Encoding")) {
-		len = strlen("Content-Transfer-Encoding: ");
-		strbuf_add(&sb, line->buf + len, line->len - len);
-		decode_header(mi, &sb);
+	if (parse_header(line, "Content-Transfer-Encoding", mi, &sb)) {
 		handle_content_transfer_encoding(mi, &sb);
 		ret = 1;
 		goto check_header_out;
 	}
-	if (cmp_header(line, "Message-Id")) {
-		len = strlen("Message-Id: ");
-		strbuf_add(&sb, line->buf + len, line->len - len);
-		decode_header(mi, &sb);
+	if (parse_header(line, "Message-Id", mi, &sb)) {
 		if (mi->add_message_id)
 			mi->message_id = strbuf_detach(&sb, NULL);
 		ret = 1;
@@ -607,8 +618,9 @@ static int is_inbody_header(const struct mailinfo *mi,
 			    const struct strbuf *line)
 {
 	int i;
+	const char *val;
 	for (i = 0; header[i]; i++)
-		if (!mi->s_hdr_data[i] && cmp_header(line, header[i]))
+		if (!mi->s_hdr_data[i] && skip_header(line, header[i], &val))
 			return 1;
 	return 0;
 }
@@ -1126,6 +1138,11 @@ static void handle_info(struct mailinfo *mi)
 		else
 			continue;
 
+		if (memchr(hdr->buf, '\0', hdr->len)) {
+			error("a NUL byte in '%s' is not allowed.", header[i]);
+			mi->input_error = -1;
+		}
+
 		if (!strcmp(header[i], "Subject")) {
 			if (!mi->keep_subject) {
 				cleanup_subject(mi, hdr);