From 0b6199228848524a4b2ecfd4ab36a4da37312391 Mon Sep 17 00:00:00 2001
From: Yihui Xie <xie@yihui.name>
Date: Thu, 6 Aug 2015 23:22:35 -0500
Subject: [PATCH] fixes rstudio/htmltools#30: when HTML code is empty, do not
 try to base64 encode images

---
 NEWS               | 7 +++++++
 R/renderMarkdown.R | 1 +
 2 files changed, 8 insertions(+)

diff --git a/NEWS b/NEWS
index 92b107c..c439532 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,10 @@
+			      CHANGES IN markdown VERSION 0.7.8
+
+BUG FIXES
+
+   o fixed https://github.com/rstudio/htmltools/issues/30: markdownToHTML() did
+   not work with empty files (thanks, @VermillionAzure)
+
 			      CHANGES IN markdown VERSION 0.7.7
 
 BUG FIXES
diff --git a/R/renderMarkdown.R b/R/renderMarkdown.R
index 79571a3..e6e85cb 100644
--- a/R/renderMarkdown.R
+++ b/R/renderMarkdown.R
@@ -158,6 +158,7 @@ renderMarkdown <- function(
 
 
 .b64EncodeImages <- function(html) {
+  if (length(html) == 0) return(html)
   reg <- "<\\s*[Ii][Mm][Gg]\\s+[Ss][Rr][Cc]\\s*=\\s*[\"']([^\"']+)[\"']"
   m <- gregexpr(reg, html, perl = TRUE)
   if (m[[1]][1] != -1) {