[meld] sourceview: Base x-coords for drawing on clip area, not allocation

[Kai Willadsen <kaiw src gnome org>]

commit 9f32ab78a28d574b3116573b4fa0d4078326697a
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Oct 10 07:07:52 2015 +1000

    sourceview: Base x-coords for drawing on clip area, not allocation
    
    The visible effect of this bug was that when scrolling horizontally,
    areas would sometimes be left unpainted. This was because of the new
    text view pixel cache, which sets clip areas to exceed the actual
    visible area.
    
    We've already fixed this for vertical allocations; this commit just
    fixes the bug for horizontal coordinates as well.

 meld/sourceview.py |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)
---
diff --git a/meld/sourceview.py b/meld/sourceview.py
index 05dbcab..9f49ed1 100644
--- a/meld/sourceview.py
+++ b/meld/sourceview.py
@@ -183,7 +183,8 @@ class MeldSourceView(GtkSource.View):
                   self.get_line_num_for_y(buffer_y_end))
 
         visible = self.get_visible_rect()
-        width = self.get_allocation().width
+        x = clip.x - 0.5
+        width = clip.width + 1
 
         # Paint chunk backgrounds and outlines
         for change in self.chunk_iter(bounds):
@@ -191,7 +192,7 @@ class MeldSourceView(GtkSource.View):
             ypos1 = self.get_y_for_line_num(change[2]) - visible.y
             height = max(0, ypos1 - ypos0 - 1)
 
-            context.rectangle(-0.5, ypos0 + 0.5, width + 1, height)
+            context.rectangle(x, ypos0 + 0.5, width, height)
             if change[1] != change[2]:
                 context.set_source_rgba(*self.fill_colors[change[0]])
                 context.fill_preserve()
@@ -210,7 +211,7 @@ class MeldSourceView(GtkSource.View):
             it = textbuffer.get_iter_at_mark(textbuffer.get_insert())
             ypos, line_height = self.get_line_yrange(it)
             context.save()
-            context.rectangle(0, ypos - visible.y, width, line_height)
+            context.rectangle(x, ypos - visible.y, width, line_height)
             context.clip()
             context.set_source_rgba(*self.highlight_color)
             context.paint_with_alpha(0.25)
@@ -223,7 +224,7 @@ class MeldSourceView(GtkSource.View):
             syncline = textbuffer.get_iter_at_mark(syncpoint).get_line()
             if bounds[0] <= syncline <= bounds[1]:
                 ypos = self.get_y_for_line_num(syncline) - visible.y
-                context.rectangle(-0.5, ypos - 0.5, width + 1, 1)
+                context.rectangle(x, ypos - 0.5, width, 1)
                 context.set_source_rgba(*self.syncpoint_color)
                 context.stroke()
 
@@ -243,7 +244,7 @@ class MeldSourceView(GtkSource.View):
                 ystart -= 1
 
             context.set_source_rgba(*rgba)
-            context.rectangle(0, ystart - visible.y, width, yend - ystart)
+            context.rectangle(x, ystart - visible.y, width, yend - ystart)
             context.fill()
 
             if current_time <= c.start_time + c.duration: