- Reworked a few options that previously depended on LEVEL_HEXENFORMAT

(actors being forced to the ground by instantly moving sectors, strife
  railing handling and shooting lines with a non-zero but unassigned tag.)
  With UDMF such semantics have to be handled diffently. 
- finalized UDMF 1.0 implementation.
- Added Martin Howe's latest morph update.


SVN r987 (trunk)

src/p_spec.cpp

@@ -229,11 +229,12 @@ bool P_ActivateLine (line_t *line, AActor *mo, int side, int activationType)
 	}
 	// some old WADs use this method to create walls that change the texture when shot.
 	else if (activationType == SPAC_Impact &&					// only for shootable triggers
-		!(level.flags & LEVEL_HEXENFORMAT) &&					// only in Doom-format maps
+		(level.flags & LEVEL_DUMMYSWITCHES) &&					// this is only a compatibility setting for an old hack!
 		!repeat &&												// only non-repeatable triggers
 		(special<Generic_Floor || special>Generic_Crusher) &&	// not for Boom's generalized linedefs
 		special &&												// not for lines without a special
-		line->id &&												// only if there's a tag (which is stored in the id field)
+		line->args[0] == line->id &&							// Safety check: exclude edited UDMF linedefs or ones that don't map the tag to args[0]
+		line->args[0] &&										// only if there's a tag (which is stored in the first arg)
 		P_FindSectorFromTag (line->args[0], -1) == -1)			// only if no sector is tagged to this linedef
 	{
 		P_ChangeSwitchTexture (&sides[line->sidenum[0]], repeat, special);