[PATCH 0/1] MR6843: opengl: Avoid inifinite recursion in bezier_approximate() in case of degraded curve.

[PATCH 1/1] opengl: Avoid inifinite recursion in bezier_approximate() in case of degraded curve.

[Paul Gofman]

From: Paul Gofman

---
 dlls/opengl32/wgl.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/dlls/opengl32/wgl.c b/dlls/opengl32/wgl.c
index c6414054ff5..eac22011e08 100644
--- a/dlls/opengl32/wgl.c
+++ b/dlls/opengl32/wgl.c
@@ -1176,7 +1176,7 @@ typedef struct _bezier_vector {
     GLdouble y;
 } bezier_vector;

-static double bezier_deviation_squared(const bezier_vector *p)
+static BOOL bezier_fits_deviation(const bezier_vector *p, FLOAT max_deviation)
 {
     bezier_vector deviation;
     bezier_vector vertex;
@@ -1184,6 +1184,8 @@ static double bezier_deviation_squared(const bezier_vector *p)
     double base_length;
     double dot;

+    max_deviation *= max_deviation;
+
     vertex.x = (p[0].x + p[1].x*2 + p[2].x)/4 - p[0].x;
     vertex.y = (p[0].y + p[1].y*2 + p[2].y)/4 - p[0].y;

@@ -1191,6 +1193,7 @@ static double bezier_deviation_squared(const bezier_vector *p)
     base.y = p[2].y - p[0].y;

base_length = sqrt(base.x*base.x + base.y*base.y);
+    if (base_length <= max_deviation) return TRUE;
     base.x /= base_length;
     base.y /= base_length;

@@ -1202,7 +1205,7 @@ static double bezier_deviation_squared(const bezier_vector *p)
     deviation.x = vertex.x-base.x;
     deviation.y = vertex.y-base.y;

-    return deviation.x*deviation.x + deviation.y*deviation.y;
+    return deviation.x*deviation.x + deviation.y*deviation.y <= max_deviation;
 }

static int bezier_approximate(const bezier_vector *p, bezier_vector *points, FLOAT deviation)
@@ -1212,7 +1215,7 @@ static int bezier_approximate(const bezier_vector *p, bezier_vector *points, FLO
     bezier_vector vertex;
     int total_vertices;

-    if(bezier_deviation_squared(p) <= deviation*deviation)
+    if (bezier_fits_deviation(p, deviation))
     {
         if(points)
             *points = p[2];

[PATCH 1/1] opengl: Avoid inifinite recursion in bezier_approximate() in case of degraded curve.

[Marvin]

Hi,

It looks like your patch introduced the new failures shown below.
Please investigate and fix them before resubmitting your patch.
If they are not new, fixing them anyway would help a lot. Otherwise
please ask for the known failures list to be updated.

The tests also ran into some preexisting test failures. If you know how
to fix them that would be helpful. See the TestBot job for the details:

The full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=149754

Your paranoid android.

=== debian11b (64 bit WoW report) ===

user32:
win.c:4070: Test failed: Expected active window 0000000003F00158, got 0000000000000000.
win.c:4071: Test failed: Expected focus window 0000000003F00158, got 0000000000000000.

[Paul Gofman (＠gofman)]

Fixes a crash / hang on start in Soul Interface.

When a glyph spline curve ends up with duplicated point(s) that currently causes bezier_deviation_squared() to return NAN (because of division into zero base_length) yielding infinite recursion in bezier_approximate().

[Haoyang Chen (＠chenhaoyang)]

'inifinite' word spell error in commit-msg.