qbsp: fix handling of duplicate planes

fixes spurious leak in e1m4.map

include/qbsp/brush.hh

@@ -37,6 +37,7 @@ class mapbrush_t;
 
 int Brush_ListCountWithCFlags(const brush_t *brush, int cflags);
 int Brush_ListCount(const brush_t *brush);
+int Brush_NumFaces(const brush_t *brush);
 
 brush_t *LoadBrush(const mapbrush_t *mapbrush, const vec3_t rotate_offset, const int hullnum);
 void FreeBrushes(brush_t *brushlist);

qbsp/brush.cc

@@ -929,6 +929,19 @@ Brush_ListCount(const brush_t *brush)
     return Brush_ListCountWithCFlags(brush, 0);
 }
 
+static int FaceListCount(const face_t *facelist)
+{
+    if (facelist)
+        return 1 + FaceListCount(facelist->next);
+    else
+        return 0;
+}
+
+int Brush_NumFaces(const brush_t *brush)
+{
+    return FaceListCount(brush->faces);
+}
+
 void
 Entity_SortBrushes(mapentity_t *dst)
 {

qbsp/map.cc

@@ -1476,10 +1476,12 @@ ParseBrush(parser_t *parser, const mapentity_t *entity)
             continue;
 
         /* Check for duplicate planes */
+        bool discardFace = false;
         for (int i = 0; i<brush.numfaces; i++) {
             const mapface_t &check = brush.face(i);
             if (PlaneEqual(&check.plane, &face->plane)) {
                 Message(msgWarning, warnBrushDuplicatePlane, parser->linenum);
+                discardFace = true;
                 continue;
             }
             if (PlaneInvEqual(&check.plane, &face->plane)) {
@@ -1488,6 +1490,8 @@ ParseBrush(parser_t *parser, const mapentity_t *entity)
                 continue;
             }
         }
+        if (discardFace)
+            continue;
 
         /* Save the face, update progress */
         

qbsp/test_qbsp.cc

@@ -23,8 +23,8 @@ static const mapface_t *Mapbrush_FirstFaceWithTextureName(const mapbrush_t *brus
     return nullptr;
 }
 
-static std::array<qvec4f, 2>
-GetTexvecs(const char *map, const char *texname)
+static mapentity_t
+LoadMap(const char *map)
 {
     parser_t parser;
     ParserInit(&parser, map);
@@ -33,6 +33,14 @@ GetTexvecs(const char *map, const char *texname)
     // FIXME: adds the brush to the global map...
     Q_assert(ParseEntity(&parser, &worldspawn));
     
+    return worldspawn;
+}
+
+static std::array<qvec4f, 2>
+GetTexvecs(const char *map, const char *texname)
+{
+    mapentity_t worldspawn = LoadMap(map);
+    
     const mapbrush_t *mapbrush = &worldspawn.mapbrush(0);
     const mapface_t *mapface = Mapbrush_FirstFaceWithTextureName(mapbrush, "tech02_1");
     Q_assert(nullptr != mapface);
@@ -84,3 +92,31 @@ TEST(qbsp, testTextureIssue) {
     }
 #endif
 }
+
+TEST(qbsp, duplicatePlanes) {
+    // a brush from e1m4.map with 7 planes, only 6 unique.
+    const char *mapWithDuplicatePlanes = R"(
+    {
+        "classname"	"worldspawn"
+        {
+            ( 512 120 1184 ) ( 512 104 1184 ) ( 512 8 1088 ) WBRICK1_5 0 0 0 1.000000 1.000000
+            ( 1072 104 1184 ) ( 176 104 1184 ) ( 176 8 1088 ) WBRICK1_5 0 0 0 1.000000 1.000000
+            ( 896 56 1184 ) ( 896 72 1184 ) ( 896 -24 1088 ) WBRICK1_5 0 0 0 1.000000 1.000000
+            ( 176 88 1184 ) ( 1072 88 1184 ) ( 1072 -8 1088 ) WBRICK1_5 0 0 0 1.000000 1.000000
+            ( 176 88 1184 ) ( 176 104 1184 ) ( 1072 104 1184 ) WBRICK1_5 0 0 0 1.000000 1.000000
+            ( 1072 8 1088 ) ( 176 8 1088 ) ( 176 -8 1088 ) WBRICK1_5 0 0 0 1.000000 1.000000
+            ( 960 8 1088 ) ( 864 104 1184 ) ( 848 104 1184 ) WBRICK1_5 0 0 0 1.000000 1.000000
+        }
+    }
+    )";
+    
+    mapentity_t worldspawn = LoadMap(mapWithDuplicatePlanes);
+    ASSERT_EQ(1, worldspawn.nummapbrushes);
+    EXPECT_EQ(0, worldspawn.numbrushes);
+    EXPECT_EQ(6, worldspawn.mapbrush(0).numfaces);
+    
+    brush_t *brush = LoadBrush(&worldspawn.mapbrush(0), vec3_origin, 0);
+    ASSERT_NE(nullptr, brush);
+    EXPECT_EQ(6, Brush_NumFaces(brush));
+    FreeMem(brush, BRUSH, 1);
+}