Check for empty string before trying to look at line ending.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/blocks.c b/src/blocks.c
index 38450e0..6b2e14d 100755
--- a/src/blocks.c
+++ b/src/blocks.c
@@ -600,7 +600,7 @@ static void S_process_line(cmark_parser *parser, const unsigned char *buffer,
     cmark_strbuf_put(parser->curline, buffer, bytes);
   }
   // ensure line ends with a newline:
-  if (!S_is_line_end_char(parser->curline->ptr[bytes - 1])) {
+  if (bytes == 0 || !S_is_line_end_char(parser->curline->ptr[bytes - 1])) {
 	  cmark_strbuf_putc(parser->curline, '\n');
   }
   parser->offset = 0;