Fix #21369: normals on extruded text and curve objects were flipped

for the backside, giving problems with e.g. boolean operations.

source/blender/blenkernel/BKE_displist.h

@@ -99,7 +99,7 @@ extern void shadeMeshMCol(struct Scene *scene, struct Object *ob, struct Mesh *m
 int surfindex_displist(DispList *dl, int a, int *b, int *p1, int *p2, int *p3, int *p4);
 void imagestodisplist(void);
 void reshadeall_displist(struct Scene *scene);
-void filldisplist(struct ListBase *dispbase, struct ListBase *to);
+void filldisplist(struct ListBase *dispbase, struct ListBase *to, int flipnormal);
 
 void fastshade_free_render(void);
 

source/blender/blenkernel/intern/displist.c

@@ -925,7 +925,7 @@ static void curve_to_displist(Curve *cu, ListBase *nubase, ListBase *dispbase)
 }
 
 
-void filldisplist(ListBase *dispbase, ListBase *to)
+void filldisplist(ListBase *dispbase, ListBase *to, int flipnormal)
 {
 	EditVert *eve, *v1, *vlast;
 	EditFace *efa;
@@ -1019,6 +1019,9 @@ void filldisplist(ListBase *dispbase, ListBase *to)
 					index[0]= (intptr_t)efa->v1->tmp.l;
 					index[1]= (intptr_t)efa->v2->tmp.l;
 					index[2]= (intptr_t)efa->v3->tmp.l;
+
+					if(flipnormal)
+						SWAP(int, index[0], index[2]);
 					
 					index+= 3;
 					efa= efa->next;
@@ -1095,13 +1098,13 @@ static void bevels_to_filledpoly(Curve *cu, ListBase *dispbase)
 		dl= dl->next;
 	}
 
-	filldisplist(&front, dispbase);
-	filldisplist(&back, dispbase);
+	filldisplist(&front, dispbase, 1);
+	filldisplist(&back, dispbase, 0);
 	
 	freedisplist(&front);
 	freedisplist(&back);
 
-	filldisplist(dispbase, dispbase);
+	filldisplist(dispbase, dispbase, 0);
 	
 }
 
@@ -1113,7 +1116,7 @@ static void curve_to_filledpoly(Curve *cu, ListBase *nurb, ListBase *dispbase)
 		bevels_to_filledpoly(cu, dispbase);
 	}
 	else {
-		filldisplist(dispbase, dispbase);
+		filldisplist(dispbase, dispbase, 0);
 	}
 }
 
@@ -1315,7 +1318,7 @@ static void curve_calc_modifiers_post(Scene *scene, Object *ob, ListBase *dispba
 	ModifierData *preTesselatePoint;
 	Curve *cu= ob->data;
 	ListBase *nurb= cu->editnurb?cu->editnurb:&cu->nurb;
-	int required_mode, totvert;
+	int required_mode, totvert = 0;
 	int editmode = (!forRender && cu->editnurb);
 	DerivedMesh *dm= NULL, *ndm;
 	float (*vertCos)[3] = NULL;

source/blender/editors/mesh/editmesh_mods.c

@@ -186,7 +186,7 @@ static void draw_triangulated(short mcords[][2], short tot)
 	}
 	
 	/* do the fill */
-	filldisplist(&lb, &lb);
+	filldisplist(&lb, &lb, 0);
 
 	/* do the draw */
 	dl= lb.first;	/* filldisplist adds in head of list */

source/blender/python/generic/geometry.c

@@ -419,7 +419,7 @@ static PyObject *M_Geometry_PolyFill( PyObject * self, PyObject * polyLineSeq )
 	}
 	else if (totpoints) {
 		/* now make the list to return */
-		filldisplist(&dispbase, &dispbase);
+		filldisplist(&dispbase, &dispbase, 0);
 		
 		/* The faces are stored in a new DisplayList
 		thats added to the head of the listbase */