diff --git a/regression_tests/q3map2/piercing_triangle/README.txt b/regression_tests/q3map2/piercing_triangle/README.txt
new file mode 100644
index 00000000..b09e2c31
--- /dev/null
+++ b/regression_tests/q3map2/piercing_triangle/README.txt
@@ -0,0 +1,14 @@
+DESCRIPTION OF PROBLEM:
+=======================
+
+In the disappearing_triangle regression test I outlined a potential problem
+in the tjunction.c code, having to do with 2 points being too close together
+on a winding, and that winding becoming invalid (drawsurf disappearing).
+
+This example map is the same as disappearing_triangle.map, except that the
+floor is raised by 1 unit.  Therefore the floor intersects the sliver triangle.
+The resulting chopped sliver has a very short edge that is "degenerate" and
+causes that draw surf to go away due to problems in the tjunction.c code.
+
+This is speculation at this point.  I will provide more info after the bug has
+been fixed.
diff --git a/regression_tests/q3map2/piercing_triangle/maps/piercing_triangle.map b/regression_tests/q3map2/piercing_triangle/maps/piercing_triangle.map
new file mode 100644
index 00000000..b7a3fe10
--- /dev/null
+++ b/regression_tests/q3map2/piercing_triangle/maps/piercing_triangle.map
@@ -0,0 +1,84 @@
+// entity 0
+{
+"classname" "worldspawn"
+// brush 0
+{
+( 134 -1015 0 ) ( 134 -4096 0 ) ( 67 -1022 0 ) common/caulk 0 0 0 0.500000 0.500000 134217728 4 0
+( 88 -892 -768 ) ( 88 -4096 -768 ) ( 134 -1015 0 ) common/caulk 0 0 0 0.500000 0.500000 134217728 4 0
+( 67 -1022 0 ) ( 88 -892 -768 ) ( 134 -1015 0 ) radiant_regression_tests/tile 0 0 0 0.500000 0.500000 134217728 0 0
+( 67 -1022 0 ) ( 67 -4096 0 ) ( 88 -892 -768 ) common/caulk 0 0 0 0.500000 0.500000 134217728 4 0
+( -704 -1152 0 ) ( 4480 -1152 0 ) ( -704 -1152 -768 ) common/caulk 0 0 0 0.500000 0.500000 134217728 4 0
+}
+// brush 1
+{
+( 512 -640 0 ) ( 512 -1160 0 ) ( 512 -1160 -768 ) radiant_regression_tests/tile 0 0 0 0.500000 0.500000 0 0 0
+( 584 -640 0 ) ( 520 -640 0 ) ( 520 -640 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 520 -1160 0 ) ( 520 -640 0 ) ( 520 -640 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 528 -1152 0 ) ( 592 -1152 0 ) ( 592 -1152 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 528 -1160 320 ) ( 528 -640 320 ) ( 592 -640 320 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 583 -640 -768 ) ( 519 -640 -768 ) ( 519 -1160 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+}
+// brush 2
+{
+( -512 -536 320 ) ( -512 -624 320 ) ( -512 -624 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 528 -632 320 ) ( -280 -632 320 ) ( -280 -632 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 512 -640 320 ) ( 512 -552 320 ) ( 512 -552 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( -296 -640 320 ) ( 512 -640 320 ) ( 512 -640 -768 ) radiant_regression_tests/tile 0 0 0 0.500000 0.500000 0 0 0
+( -296 -640 320 ) ( -296 -552 320 ) ( 512 -552 320 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 511 -552 -768 ) ( -297 -552 -768 ) ( -297 -640 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+}
+// brush 3
+{
+( -520 -648 320 ) ( -520 -1152 320 ) ( -520 -1152 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( -512 -640 320 ) ( -536 -640 320 ) ( -536 -640 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( -512 -1152 320 ) ( -512 -648 320 ) ( -512 -648 -768 ) radiant_regression_tests/tile 0 0 0 0.500000 0.500000 0 0 0
+( -536 -1152 320 ) ( -512 -1152 320 ) ( -512 -1152 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( -536 -1152 320 ) ( -536 -648 320 ) ( -512 -648 320 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( -512 -648 -768 ) ( -536 -648 -768 ) ( -536 -1152 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+}
+// brush 4
+{
+( -512 -640 464 ) ( -512 -1152 464 ) ( -512 -1152 352 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 512 -640 440 ) ( 24 -640 440 ) ( 24 -640 328 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 512 -1152 440 ) ( 512 -640 440 ) ( 512 -640 328 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 24 -1152 440 ) ( 512 -1152 440 ) ( 512 -1152 328 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 48 -1152 328 ) ( 48 -640 328 ) ( 536 -640 328 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 512 -640 320 ) ( 24 -640 320 ) ( 24 -1152 320 ) radiant_regression_tests/tile 0 0 0 0.500000 0.500000 0 0 0
+}
+// brush 5
+{
+( -368 -640 -824 ) ( -856 -640 -824 ) ( -856 -640 -960 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 512 -1152 -768 ) ( 512 -896 -768 ) ( 512 -896 -776 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( -512 -896 -768 ) ( -512 -1152 -768 ) ( -512 -1152 -776 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( -512 -1152 -768 ) ( -328 -1152 -768 ) ( -328 -1152 -776 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( -511 -1152 -767 ) ( -511 -896 -767 ) ( -327 -896 -767 ) radiant_regression_tests/tile 0 0 0 0.500000 0.500000 0 0 0
+( -328 -896 -776 ) ( -512 -896 -776 ) ( -512 -1152 -776 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+}
+// brush 6
+{
+( -256 -1152 -768 ) ( -520 -1152 -768 ) ( -520 -1192 -768 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 176 -1568 320 ) ( 176 -1152 320 ) ( 1152 -1152 320 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 208 -1160 320 ) ( 1184 -1160 320 ) ( 1184 -1160 0 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 512 -1576 320 ) ( 512 -1160 320 ) ( 512 -1160 0 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+( 1152 -1152 320 ) ( 176 -1152 320 ) ( 176 -1152 0 ) radiant_regression_tests/tile 0 0 0 0.500000 0.500000 0 0 0
+( -512 -1168 320 ) ( -512 -1584 320 ) ( -512 -1584 0 ) common/caulk 0 0 0 0.500000 0.500000 0 4 0
+}
+}
+// entity 1
+{
+"classname" "light"
+"origin" "0 -768 -480"
+"light" "3000"
+}
+// entity 2
+{
+"classname" "info_player_deathmatch"
+"origin" "0 -712 -640"
+"angle" "270"
+}
+// entity 3
+{
+"light" "3000"
+"origin" "0 -832 160"
+"classname" "light"
+}
diff --git a/regression_tests/q3map2/piercing_triangle/textures/radiant_regression_tests/tile.tga b/regression_tests/q3map2/piercing_triangle/textures/radiant_regression_tests/tile.tga
new file mode 100644
index 00000000..2154015f
Binary files /dev/null and b/regression_tests/q3map2/piercing_triangle/textures/radiant_regression_tests/tile.tga differ