xserver: Branch 'master'

[Keith Packard]

 fb/fbseg.c |   20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

New commits:
commit 1b94fd77792310c80b0a2bcf4bf6d4e4c4c23bca
Author: Alex Orange <crazycasta at gmail.com>
Date:   Fri Oct 3 15:41:38 2014 -0600

    fb: Fix Bresenham algorithms for commonly used small segments.
    
    Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=54168
    
    Fix errors introducted in 863d528a9f76d0e8f122aebf19f8564a4c67a938. Said
    patch does indeed remove the problematic writes to bad memory, however
    it also introduces errors in the algoritm. This patch has the effect of
    reverting said patch and adding an if in the proper location to catch
    the out of bounds memory write without causing problems to the overall
    algorithm.
    
    Signed-off-by: Alex Orange <crazycasta at gmail.com>
    Reviewed-by: Peter Harris <pharris at opentext.com>
    Tested-by: Peter Harris <pharris at opentext.com>
    Signed-off-by: Keith Packard <keithp at keithp.com>

diff --git a/fb/fbseg.c b/fb/fbseg.c
index 36b17e3..c3c196a 100644
--- a/fb/fbseg.c
+++ b/fb/fbseg.c
@@ -65,12 +65,6 @@ fbBresSolid(DrawablePtr pDrawable,
     if (axis == X_AXIS) {
         bits = 0;
         while (len--) {
-            if (e >= 0) {
-                WRITE(dst, FbDoMaskRRop (READ(dst), and, xor, bits));
-                bits = 0;
-                dst += dstStride;
-                e += e3;
-            }
             bits |= mask;
             mask = fbBresShiftMask(mask, signdx, dstBpp);
             if (!mask) {
@@ -80,12 +74,23 @@ fbBresSolid(DrawablePtr pDrawable,
                 mask = mask0;
             }
             e += e1;
+            if (e >= 0) {
+                if (bits) {
+                    WRITE(dst, FbDoMaskRRop (READ(dst), and, xor, bits));
+                    bits = 0;
+                }
+                dst += dstStride;
+                e += e3;
+            }
         }
         if (bits)
             WRITE(dst, FbDoMaskRRop(READ(dst), and, xor, bits));
     }
     else {
         while (len--) {
+            WRITE(dst, FbDoMaskRRop(READ(dst), and, xor, mask));
+            dst += dstStride;
+            e += e1;
             if (e >= 0) {
                 e += e3;
                 mask = fbBresShiftMask(mask, signdx, dstBpp);
@@ -94,9 +99,6 @@ fbBresSolid(DrawablePtr pDrawable,
                     mask = mask0;
                 }
             }
-            WRITE(dst, FbDoMaskRRop(READ(dst), and, xor, mask));
-            dst += dstStride;
-            e += e1;
         }
     }