[continuecomment addon] Allow continuing block comment from first line.

addon/comment/continuecomment.js

@@ -12,7 +12,7 @@
     if (mode.blockCommentStart && mode.blockCommentContinue) {
       var end = token.string.indexOf(mode.blockCommentEnd);
       var full = cm.getRange(CodeMirror.Pos(pos.line, 0), CodeMirror.Pos(pos.line, token.end)), found;
-      if (end != -1 && end == token.string.length - mode.blockCommentEnd.length) {
+      if (end != -1 && end == token.string.length - mode.blockCommentEnd.length && pos.ch >= end) {
         // Comment ended, don't continue it
       } else if (token.string.indexOf(mode.blockCommentStart) == 0) {
         insert = full.slice(0, token.start);