Fixed|libcommon|XG: Erroneous attempt to allocate dummy map line sides

As of Doomsday 1.10 the sides of a map line are now automatically
allocated along with the line itself. XG was attempting to allocate
additional sides and then link them to a dummy line itself.

doomsday/plugins/common/include/dmu_lib.h

@@ -159,10 +159,6 @@ Line *P_AllocDummyLine(void);
 
 void P_FreeDummyLine(Line *line);
 
-Side *P_AllocDummySide(void);
-
-void P_FreeDummySide(Side *side);
-
 /**
  * Get the sector on the other side of the line that is NOT the given sector.
  *

doomsday/plugins/common/src/dmu_lib.cpp

@@ -51,16 +51,6 @@ void P_FreeDummyLine(Line *line)
     P_FreeDummy(line);
 }
 
-Side *P_AllocDummySide()
-{
-    return (Side *)P_AllocDummy(DMU_SIDE, 0);
-}
-
-void P_FreeDummySide(Side *side)
-{
-    P_FreeDummy(side);
-}
-
 void P_CopyLine(Line *dest, Line *src)
 {
     xline_t *xsrc  = P_ToXLine(src);

doomsday/plugins/common/src/p_xgline.c

@@ -2523,23 +2523,14 @@ int XL_HitLine(Line *line, int sidenum, mobj_t *thing)
 
 void XL_DoChain(Line *line, int chain, boolean activating, mobj_t *actThing)
 {
-    Side *dummyFrontSideDef, *dummyBackSideDef = NULL;
-    Line *dummyLineDef;
-    xline_t *xdummyLineDef;
+    // We'll use a dummy for the chain.
+    Line *dummyLineDef     = P_AllocDummyLine();
+    xline_t *xdummyLineDef = P_ToXLine(dummyLineDef);
 
-    // We'll use dummies for the chain.
-    dummyLineDef = P_AllocDummyLine();
-    xdummyLineDef = P_ToXLine(dummyLineDef);
     xdummyLineDef->xg = Z_Calloc(sizeof(xgline_t), PU_MAP, 0);
-    dummyFrontSideDef = P_AllocDummySide();
-    P_SetPtrp(dummyLineDef, DMU_FRONT, dummyFrontSideDef);
-    P_SetPtrp(dummyFrontSideDef, DMU_LINE, dummyLineDef);
     P_SetPtrp(dummyLineDef, DMU_FRONT_SECTOR, P_GetPtrp(line, DMU_FRONT_SECTOR));
     if(0 != P_GetPtrp(line, DMU_BACK))
     {
-        dummyBackSideDef = P_AllocDummySide();
-        P_SetPtrp(dummyLineDef, DMU_BACK, dummyBackSideDef);
-        P_SetPtrp(dummyBackSideDef, DMU_LINE, dummyLineDef);
         P_SetPtrp(dummyLineDef, DMU_BACK_SECTOR, P_GetPtrp(line, DMU_BACK_SECTOR));
     }
 
@@ -2556,9 +2547,6 @@ void XL_DoChain(Line *line, int chain, boolean activating, mobj_t *actThing)
 
     Z_Free(xdummyLineDef->xg);
     P_FreeDummyLine(dummyLineDef);
-    P_FreeDummySide(dummyFrontSideDef);
-    if(dummyBackSideDef)
-        P_FreeDummySide(dummyBackSideDef);
 }
 
 /**

doomsday/plugins/common/src/p_xgsec.c

@@ -2616,15 +2616,14 @@ void XS_UpdateLight(Sector* sec)
     }
 }
 
-void XS_DoChain(Sector* sec, int ch, int activating, void* act_thing)
+void XS_DoChain(Sector *sec, int ch, int activating, void *act_thing)
 {
-    xgsector_t* xg;
-    sectortype_t* info;
+    xgsector_t *xg;
+    sectortype_t *info;
     float flevtime = TIC2FLT(mapTime);
-    Line* dummyLine;
-    xline_t* xdummyLine;
-    linetype_t* ltype;
-    Side* dummySideDef;
+    Line *dummyLine;
+    xline_t *xdummyLine;
+    linetype_t *ltype;
 
     xg = P_ToXSector(sec)->xg;
     info = &xg->info;
@@ -2650,11 +2649,8 @@ void XS_DoChain(Sector* sec, int ch, int activating, void* act_thing)
     dummyLine = P_AllocDummyLine();
     xdummyLine = P_ToXLine(dummyLine);
     xdummyLine->xg = Z_Calloc(sizeof(xgline_t), PU_MAP, 0);
-    dummySideDef = P_AllocDummySide();
 
-    P_SetPtrp(dummyLine, DMU_FRONT, dummySideDef);
     P_SetPtrp(dummyLine, DMU_FRONT_SECTOR, sec);
-    P_SetPtrp(dummySideDef, DMU_LINE, dummyLine);
 
     xdummyLine->special = (ch == XSCE_FUNCTION ? activating : info->chain[ch]);
 
@@ -2708,7 +2704,6 @@ void XS_DoChain(Sector* sec, int ch, int activating, void* act_thing)
     // We're done, free the dummies.
     Z_Free(xdummyLine->xg);
     P_FreeDummyLine(dummyLine);
-    P_FreeDummySide(dummySideDef);
 }
 
 static boolean checkChainRequirements(Sector* sec, mobj_t* mo, int ch,