--- /dev/null
+From 43549773608b4f58dc664b7115a1ef0dcb32f251 Mon Sep 17 00:00:00 2001
+From: Haihua Hu <jared.hu@nxp.com>
+Date: Tue, 14 Jun 2016 13:48:09 +0800
+Subject: [PATCH 1/2] [glplugin]gleffects: fix little rectangel appears at the
+ center when use squeeze and tunnel effects
+
+These two shader will calculate the verctor length and use it as denominator.
+But length could be zero which will cause undefine behaviour. Add protection for
+this condition
+
+Upstream-Status: Backport [1.8.3]
+
+https://bugzilla.gnome.org/show_bug.cgi?id=767635
+
+Signed-off-by: Haihua Hu <jared.hu@nxp.com>
+---
+ ext/gl/effects/gstgleffectssources.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/ext/gl/effects/gstgleffectssources.c b/ext/gl/effects/gstgleffectssources.c
+index 6bdc155..3e87b8b 100644
+--- a/ext/gl/effects/gstgleffectssources.c
++++ b/ext/gl/effects/gstgleffectssources.c
+@@ -100,7 +100,8 @@ const gchar *squeeze_fragment_source_gles2 =
+ "void main () {"
+ " vec2 texturecoord = v_texcoord.xy;"
+ " vec2 normcoord = texturecoord - 0.5;"
+- " float r = length (normcoord);"
++ /* Add a very small value to length otherwise it could be 0 */
++ " float r = length (normcoord)+0.01;"
+ " r = pow(r, 0.40)*1.3;"
+ " normcoord = normcoord / r;"
+ " texturecoord = (normcoord + 0.5);"
+@@ -136,7 +137,8 @@ const gchar *tunnel_fragment_source_gles2 =
+ * rect textures */
+ " normcoord = (texturecoord - 0.5);"
+ " float r = length(normcoord);"
+- " normcoord *= clamp (r, 0.0, 0.275) / r;"
++ " if (r > 0.0)"
++ " normcoord *= clamp (r, 0.0, 0.275) / r;"
+ " texturecoord = normcoord + 0.5;"
+ " gl_FragColor = texture2D (tex, texturecoord);"
+ "}";
+--
+1.9.1
+
