diff --git a/src/fragglescript/t_func.cpp b/src/fragglescript/t_func.cpp
index 0251b8fba..a0609377e 100644
--- a/src/fragglescript/t_func.cpp
+++ b/src/fragglescript/t_func.cpp
@@ -67,6 +67,7 @@
 #include "v_font.h"
 #include "r_data/colormaps.h"
 #include "farchive.h"
+#include "p_setup.h"
 
 static FRandom pr_script("FScript");
 
@@ -2226,9 +2227,6 @@ void FParser::SF_RunCommand(void)
 //
 //==========================================================================
 
-// any linedef type
-extern void P_TranslateLineDef (line_t *ld, maplinedef_t *mld);
-
 void FParser::SF_LineTrigger()
 {
 	if (CheckArgs(1))
@@ -2237,7 +2235,7 @@ void FParser::SF_LineTrigger()
 		maplinedef_t mld;
 		mld.special=intvalue(t_argv[0]);
 		mld.tag=t_argc > 1 ? intvalue(t_argv[1]) : 0;
-		P_TranslateLineDef(&line, &mld);
+		P_TranslateLineDef(&line, &mld, false);
 		P_ExecuteSpecial(line.special, NULL, Script->trigger, false, 
 			line.args[0],line.args[1],line.args[2],line.args[3],line.args[4]); 
 	}
@@ -4382,15 +4380,12 @@ void FParser::SF_SetLineTrigger()
 		FLineIdIterator itr(id);
 		while ((i = itr.Next()) >= 0)
 		{
-			if (t_argc == 2) tag = lines[i].GetMainId();
 			maplinedef_t mld;
 			mld.special = spec;
 			mld.tag = tag;
 			mld.flags = 0;
 			int f = lines[i].flags;
-			P_TranslateLineDef(&lines[i], &mld);
-			lines[i].ClearIds();
-			lines[i].SetMainId(tag);
+			P_TranslateLineDef(&lines[i], &mld, false);
 			lines[i].flags = (lines[i].flags & (ML_MONSTERSCANACTIVATE | ML_REPEAT_SPECIAL | ML_SPAC_MASK | ML_FIRSTSIDEONLY)) |
 				(f & ~(ML_MONSTERSCANACTIVATE | ML_REPEAT_SPECIAL | ML_SPAC_MASK | ML_FIRSTSIDEONLY));
 
@@ -4401,26 +4396,13 @@ void FParser::SF_SetLineTrigger()
 
 //==========================================================================
 //
-// new for GZDoom: Changes a sector's tag
-// (I only need this because MAP02 in RTC-3057 has some issues with the GL 
-// renderer that I can't fix without the scripts. But loading a FS on top on
-// ACS still works so I can hack around it with this.)
+//
 //
 //==========================================================================
 
 void FParser::SF_ChangeTag()
 {
-	if (CheckArgs(2))
-	{
-		FSectorTagIterator it(t_argv[0].value.i);
-		int secnum;
-		while ((secnum = it.Next()) >= 0)
-		{
-			sectors[secnum].ClearTags();
-			sectors[secnum].SetMainTag(t_argv[1].value.i);
-		}
-		sector_t::HashTags();
-	}
+	// Development garbage!
 }
 
 
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 9c47e1fdc..4a1527514 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -96,7 +96,6 @@ CVAR (Bool, gennodes, false, CVAR_SERVERINFO|CVAR_GLOBALCONFIG);
 CVAR (Bool, genglnodes, false, CVAR_SERVERINFO);
 CVAR (Bool, showloadtimes, false, 0);
 
-static void P_InitTagLists ();
 static void P_Shutdown ();
 
 bool P_IsBuildMap(MapData *map);
@@ -2146,11 +2145,10 @@ void P_LoadLineDefs (MapData * map)
 
 		// [RH] Translate old linedef special and flags to be
 		//		compatible with the new format.
-		P_TranslateLineDef (ld, mld);
+		P_TranslateLineDef (ld, mld, true);
 
 		ld->v1 = &vertexes[LittleShort(mld->v1)];
 		ld->v2 = &vertexes[LittleShort(mld->v2)];
-		//ld->id = -1;		ID has been assigned in P_TranslateLineDef
 
 		P_SetSideNum (&ld->sidedef[0], LittleShort(mld->sidenum[0]));
 		P_SetSideNum (&ld->sidedef[1], LittleShort(mld->sidenum[1]));
@@ -3209,7 +3207,9 @@ static void P_GroupLines (bool buildmap)
 
 	// [RH] Moved this here
 	times[4].Clock();
-	P_InitTagLists();   // killough 1/30/98: Create xref tables for tags
+	// killough 1/30/98: Create xref tables for tags
+	sector_t::HashTags();
+	line_t::HashIds();
 	times[4].Unclock();
 
 	times[5].Clock();
@@ -3306,13 +3306,6 @@ void P_LoadBehavior (MapData * map)
 	}
 }
 
-// Hash the sector tags across the sectors and linedefs.
-static void P_InitTagLists ()
-{
-	sector_t::HashTags();
-	line_t::HashIds();
-}
-
 void P_GetPolySpots (MapData * map, TArray<FNodeBuilder::FPolyStart> &spots, TArray<FNodeBuilder::FPolyStart> &anchors)
 {
 	if (map->HasBehavior)
diff --git a/src/p_setup.h b/src/p_setup.h
index ee26f4c57..20caa5d76 100644
--- a/src/p_setup.h
+++ b/src/p_setup.h
@@ -115,7 +115,7 @@ struct line_t;
 struct maplinedef_t;
 
 void P_LoadTranslator(const char *lumpname);
-void P_TranslateLineDef (line_t *ld, maplinedef_t *mld);
+void P_TranslateLineDef (line_t *ld, maplinedef_t *mld, bool setlineid);
 int P_TranslateSectorSpecial (int);
 
 int GetUDMFInt(int type, int index, const char *key);
diff --git a/src/p_udmf.cpp b/src/p_udmf.cpp
index cdbb8dc4c..09cee8441 100644
--- a/src/p_udmf.cpp
+++ b/src/p_udmf.cpp
@@ -754,7 +754,7 @@ public:
 				mld.flags = 0;
 				mld.special = th->special;
 				mld.tag = th->args[0];
-				P_TranslateLineDef(&ld, &mld);
+				P_TranslateLineDef(&ld, &mld, true);
 				th->special = ld.special;
 				memcpy(th->args, ld.args, sizeof (ld.args));
 			}
@@ -1068,7 +1068,7 @@ public:
 			memset(&mld, 0, sizeof(mld));
 			mld.special = ld->special;
 			mld.tag = ld->GetMainId();
-			P_TranslateLineDef(ld, &mld);
+			P_TranslateLineDef(ld, &mld, false);
 			ld->flags = saved | (ld->flags&(ML_MONSTERSCANACTIVATE|ML_REPEAT_SPECIAL|ML_FIRSTSIDEONLY));
 		}
 		if (passuse && (ld->activation & SPAC_Use)) 
diff --git a/src/p_xlat.cpp b/src/p_xlat.cpp
index ef1e92849..4b1373817 100644
--- a/src/p_xlat.cpp
+++ b/src/p_xlat.cpp
@@ -60,7 +60,7 @@ typedef enum
 	PushMany,
 } triggertype_e;
 
-void P_TranslateLineDef (line_t *ld, maplinedef_t *mld)
+void P_TranslateLineDef (line_t *ld, maplinedef_t *mld, bool setid)
 {
 	unsigned short special = (unsigned short) LittleShort(mld->special);
 	short tag = LittleShort(mld->tag);
@@ -100,12 +100,14 @@ void P_TranslateLineDef (line_t *ld, maplinedef_t *mld)
 	}
 	flags = newflags;
 
-	// For purposes of maintaining BOOM compatibility, each
-	// line also needs to have its ID set to the same as its tag.
-	// An external conversion program would need to do this more
-	// intelligently.
-	ld->ClearIds();
-	ld->SetMainId(tag);
+	if (setid)
+	{
+		// For purposes of maintaining BOOM compatibility, each
+		// line also needs to have its ID set to the same as its tag.
+		// An external conversion program would need to do this more
+		// intelligently.
+		ld->SetMainId(tag);
+	}
 
 	// 0 specials are never translated.
 	if (special == 0)
diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index cb59f8a1f..b63ba567f 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -70,6 +70,7 @@
 #include "m_bbox.h"
 #include "r_data/r_translate.h"
 #include "p_trace.h"
+#include "p_setup.h"
 #include "gstrings.h"
 
 
@@ -4506,7 +4507,6 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_Weave)
 //===========================================================================
 
 
-void P_TranslateLineDef (line_t *ld, maplinedef_t *mld);
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_LineEffect)
 {
 	ACTION_PARAM_START(2);
@@ -4520,7 +4520,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_LineEffect)
 		if ((oldjunk.special = special))					// Linedef type
 		{
 			oldjunk.tag = tag;								// Sector tag for linedef
-			P_TranslateLineDef(&junk, &oldjunk);			// Turn into native type
+			P_TranslateLineDef(&junk, &oldjunk, false);			// Turn into native type
 			res = !!P_ExecuteSpecial(junk.special, NULL, self, false, junk.args[0], 
 				junk.args[1], junk.args[2], junk.args[3], junk.args[4]); 
 			if (res && !(junk.flags & ML_REPEAT_SPECIAL))	// If only once,