[geary/geary-0.11] Fix infinite loop when sending long space-stuffed line. Bug 768642.

[Michael Gratton <mjog src gnome org>]

commit 57878e063215b256a3a90e8d81a13ece4886c190
Author: Michael James Gratton <mike vee net>
Date:   Mon Aug 8 09:55:44 2016 +1000

    Fix infinite loop when sending long space-stuffed line. Bug 768642.
    
    Ported from 6aacb75 on master.
    
    * src/client/util/util-webkit.vala (Util.DOM.html_to_flowed_text): If a
      line is space-stuffed, ignore the stuffing space when determining where
      to break the line.

 src/client/util/util-webkit.vala |   16 ++++++++++++----
 1 files changed, 12 insertions(+), 4 deletions(-)
---
diff --git a/src/client/util/util-webkit.vala b/src/client/util/util-webkit.vala
index 98b06ac..032baba 100644
--- a/src/client/util/util-webkit.vala
+++ b/src/client/util/util-webkit.vala
@@ -305,7 +305,11 @@ public string decorate_quotes(string text) throws Error {
     return outtext;
 }
 
-// This will modify/reset the DOM
+/**
+ * Convert a HTML DOM tree to RFC 3676 format=flowed text.
+ *
+ * This will modify/reset the DOM.
+ */
 public string html_to_flowed_text(WebKit.DOM.HTMLElement el) {
     string saved_doc = el.get_inner_html();
     WebKit.DOM.NodeList blockquotes;
@@ -364,15 +368,19 @@ public string html_to_flowed_text(WebKit.DOM.HTMLElement el) {
         int max_len = 72 - prefix.length;
         
         do {
-            if (quote_level == 0 && (line.has_prefix(">") || line.has_prefix("From")))
+            int start_ind = 0;
+            if (quote_level == 0 &&
+                (line.has_prefix(">") || line.has_prefix("From"))) {
                 line = " " + line;
+                start_ind = 1;
+            }
             
             int cut_ind = line.length;
             if (cut_ind > max_len) {
                 string beg = line[0:max_len];
-                cut_ind = beg.last_index_of(" ") + 1;
+                cut_ind = beg.last_index_of(" ", start_ind) + 1;
                 if (cut_ind == 0) {
-                    cut_ind = line.index_of(" ") + 1;
+                    cut_ind = line.index_of(" ", start_ind) + 1;
                     if (cut_ind == 0)
                         cut_ind = line.length;
                     if (cut_ind > 998 - prefix.length)