bundle: put strbuf_readline_fd in strbuf.c with adjustments

The comment even said that it should eventually go there.  While at
it, match the calling convention and name of the function to the
strbuf_get*line family.  So it now is strbuf_getwholeline_fd.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

strbuf.c

@@ -383,6 +383,22 @@ int strbuf_getline(struct strbuf *sb, FILE *fp, int term)
 	return 0;
 }
 
+int strbuf_getwholeline_fd(struct strbuf *sb, int fd, int term)
+{
+	strbuf_reset(sb);
+
+	while (1) {
+		char ch;
+		ssize_t len = xread(fd, &ch, 1);
+		if (len <= 0)
+			return EOF;
+		strbuf_addch(sb, ch);
+		if (ch == term)
+			break;
+	}
+	return 0;
+}
+
 int strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 {
 	int fd, len;