fix for bug 1391374.

apparently, libnrtype drastically misses unit tests.

Fixed bugs:
  - https://launchpad.net/bugs/1391374

(bzr r14127)

2 files changed, 7 insertions, 3 deletions

diff --git a/src/libnrtype/Layout-TNG-OutIter.cpp b/src/libnrtype/Layout-TNG-OutIter.cpp
index c9c318960..707897f50 100644
--- a/src/libnrtype/Layout-TNG-OutIter.cpp
+++ b/src/libnrtype/Layout-TNG-OutIter.cpp
@@ -788,12 +788,12 @@ bool Layout::iterator::prevLineCursor(int n)
 {
     if (!_cursor_moving_vertically)
         beginCursorUpDown();
-    unsigned line_index;
+    int line_index;
     if (_char_index == _parent_layout->_characters.size())
         line_index = _parent_layout->_lines.size() - 1;
     else
         line_index = _parent_layout->_characters[_char_index].chunk(_parent_layout).in_line;
-    if (line_index == 0) 
+    if (line_index <= 0)
         return false; // nowhere to go
     else
         n = MIN (n, static_cast<int>(line_index));
diff --git a/src/libnrtype/Layout-TNG.h b/src/libnrtype/Layout-TNG.h
index e91c32ebe..26db1fad9 100644
--- a/src/libnrtype/Layout-TNG.h
+++ b/src/libnrtype/Layout-TNG.h
@@ -701,7 +701,11 @@ private:
 
     /** The overall block-progression of the whole flow. */
     inline Direction _blockProgression() const
-        {return static_cast<InputStreamTextSource*>(_input_stream.front())->styleGetBlockProgression();}
+        {
+            if(!_input_stream.empty())
+                return static_cast<InputStreamTextSource*>(_input_stream.front())->styleGetBlockProgression();
+            return TOP_TO_BOTTOM;
+        }
 
     /** so that LEFT_TO_RIGHT == RIGHT_TO_LEFT but != TOP_TO_BOTTOM */
     static bool _directions_are_orthogonal(Direction d1, Direction d2);