diff --git a/awk.h b/awk.h
index d9da3b9..1421203 100644
--- a/awk.h
+++ b/awk.h
@@ -631,10 +631,7 @@ typedef struct exp_instruction {
 #define sub_flags       d.dl
 #define GSUB            0x01	/* builtin is gsub */
 #define GENSUB          0x02	/* builtin is gensub */
-#define AFTER_ASSIGN    0x04	/* (g)sub target is a field or a special var with
-                            	 * set_XX routine.
-                            	 */
-#define LITERAL         0x08	/* target is a literal string */
+#define LITERAL         0x04	/* target is a literal string */
 
 
 /* Op_K_exit */
@@ -717,6 +714,9 @@ typedef struct exp_instruction {
 /* Op_field_assign */
 #define field_assign    x.aptr
 
+/* Op_field_assign, Op_var_assign */
+#define assign_ctxt	d.dl	
+
 /* Op_concat */
 #define concat_flag	    d.dl
 #define CSUBSEP			1
@@ -1192,7 +1192,7 @@ extern NODE *do_cos(int nargs);
 extern NODE *do_rand(int nargs);
 extern NODE *do_srand(int nargs);
 extern NODE *do_match(int nargs);
-extern NODE *do_sub(int nargs, unsigned int flags, int *num_matches);
+extern NODE *do_sub(int nargs, unsigned int flags);
 extern NODE *format_tree(const char *, size_t, NODE **, long);
 extern NODE *do_lshift(int nargs);
 extern NODE *do_rshift(int nargs);
diff --git a/awkgram.y b/awkgram.y
index 3ef6382..fb917c2 100644
--- a/awkgram.y
+++ b/awkgram.y
@@ -750,7 +750,6 @@ regular_loop:
 			/* add update_FOO instruction if necessary */ 
 			if ($4->array_var->type == Node_var && $4->array_var->var_update) {
 				(void) list_append(ip, instruction(Op_var_update));
-				ip->lasti->memory = $4->array_var;
 				ip->lasti->update_var = $4->array_var->var_update;
 			}
 			(void) list_append(ip, $4);
@@ -758,7 +757,6 @@ regular_loop:
 			/* add set_FOO instruction if necessary */
 			if ($4->array_var->type == Node_var && $4->array_var->var_assign) {
 				(void) list_append(ip, instruction(Op_var_assign));
-				ip->lasti->memory = $4->array_var;
 				ip->lasti->assign_var = $4->array_var->var_assign;
 			}
 
@@ -1726,7 +1724,6 @@ variable
 				&& ip->memory->var_update
 		) {
 			$$ = list_prepend($1, instruction(Op_var_update));
-			$$->nexti->memory = ip->memory;
 			$$->nexti->update_var = ip->memory->var_update;
 		} else
 			$$ = $1;
@@ -3654,14 +3651,13 @@ snode(INSTRUCTION *subn, INSTRUCTION *r)
 			/* add after_assign code */
 			if (ip->opcode == Op_push_lhs && ip->memory->type == Node_var && ip->memory->var_assign) {
 				(void) list_append(subn, instruction(Op_var_assign));
-				subn->lasti->memory = ip->memory;
+				subn->lasti->assign_ctxt = Op_sub_builtin;
 				subn->lasti->assign_var = ip->memory->var_assign;
-				r->sub_flags |= AFTER_ASSIGN;
 			} else if (ip->opcode == Op_field_spec_lhs) {
 				(void) list_append(subn, instruction(Op_field_assign));
+				subn->lasti->assign_ctxt = Op_sub_builtin;
 				subn->lasti->field_assign = (Func_ptr) 0;
 				ip->target_assign = subn->lasti;
-				r->sub_flags |= AFTER_ASSIGN;
 			}
 			return subn;	
 
@@ -5126,7 +5122,6 @@ mk_assignment(INSTRUCTION *lhs, INSTRUCTION *rhs, INSTRUCTION *op)
 		                           * for a special variable.
 		                           */
 		(void) list_append(ip, instruction(Op_var_assign));
-		ip->lasti->memory = tp->memory;
 		ip->lasti->assign_var = tp->memory->var_assign;
 	} else if (tp->opcode == Op_field_spec_lhs) {
 		(void) list_append(ip, instruction(Op_field_assign));
@@ -5323,10 +5318,11 @@ mk_getline(INSTRUCTION *op, INSTRUCTION *var, INSTRUCTION *redir, int redirtype)
 				&& tp->memory->var_assign
 		) {
 			asgn = instruction(Op_var_assign);
-			asgn->memory = tp->memory;
+			asgn->assign_ctxt = op->opcode;
 			asgn->assign_var = tp->memory->var_assign;
 		} else if (tp->opcode == Op_field_spec_lhs) {
 			asgn = instruction(Op_field_assign);
+			asgn->assign_ctxt = op->opcode;
 			asgn->field_assign = (Func_ptr) 0;   /* determined at run time */
 			tp->target_assign = asgn;
 		}
diff --git a/builtin.c b/builtin.c
index 5b75979..8685d29 100644
--- a/builtin.c
+++ b/builtin.c
@@ -2412,7 +2412,7 @@ do_match(int nargs)
  */
 
 NODE *
-do_sub(int nargs, unsigned int flags, int *num_matches)
+do_sub(int nargs, unsigned int flags)
 {
 	char *scan;
 	char *bp, *cp;
@@ -2680,7 +2680,6 @@ set_how_many:
 done:
 	DEREF(s);
 
-	*num_matches = matches;
 	if ((matches == 0 || (flags & LITERAL) != 0) && buf != NULL)
 		efree(buf); 
 
diff --git a/debug.c b/debug.c
index 404042c..4cda95c 100644
--- a/debug.c
+++ b/debug.c
@@ -39,6 +39,7 @@ extern long fcall_count;
 extern FILE *output_fp;
 extern IOBUF *curfile;
 extern const char *command_file;
+extern const char *get_spec_varname(Func_ptr fptr);
 extern int r_interpret(INSTRUCTION *);
 extern int zzparse(void);
 #define read_command()		(void) zzparse()
@@ -3736,20 +3737,19 @@ print_instruction(INSTRUCTION *pc, Func_print print_func, FILE *fp, int in_dump)
 			
 	switch (pc->opcode) {
 	case Op_var_update:
-		print_func(fp, "[update_%s]\n", pc->memory->vname);
+		print_func(fp, "[update_%s()]\n", get_spec_varname(pc->update_var));
 		break;
 
 	case Op_var_assign:
-		if (pc->assign_var)
-			print_func(fp, "[set_%s()]", pc->memory->vname);
+		print_func(fp, "[set_%s()]", get_spec_varname(pc->assign_var));
+		if (pc->assign_ctxt != 0)
+			print_func(fp, " [assign_ctxt = %s]", opcode2str(pc->assign_ctxt));
 		print_func(fp, "\n");
 		break;
 
 	case Op_field_assign:
-		if (pc->field_assign)
-			print_func(fp, "[%s]", pc->field_assign == reset_record ?
+		print_func(fp, "[%s]\n", pc->field_assign == reset_record ?
 					"reset_record()" : "invalidate_field0()");
-		print_func(fp, "\n");
 		break;
 
 	case Op_field_spec_lhs:
@@ -3843,9 +3843,8 @@ print_instruction(INSTRUCTION *pc, Func_print print_func, FILE *fp, int in_dump)
 	{
 		const char *fname = "sub";
 		static const struct flagtab values[] = {
-                	{ GSUB, "GSUB" },
+			{ GSUB, "GSUB" },
 			{ GENSUB, "GENSUB" },
-			{ AFTER_ASSIGN,	"AFTER_ASSIGN" },
 			{ LITERAL, "LITERAL" },
 			{ 0, NULL }
 		};
diff --git a/eval.c b/eval.c
index bdbd04b..bd3e027 100644
--- a/eval.c
+++ b/eval.c
@@ -2115,12 +2115,27 @@ post:
 			break;
 
 		case Op_var_assign:
-			if (pc->assign_var)
-				pc->assign_var();
-			break;
-
 		case Op_field_assign:
-			if (pc->field_assign)
+			if (pc->assign_ctxt == Op_sub_builtin
+				&& TOP()->numbr == 0.0	/* top of stack has a number == 0 */
+			) {
+				/* There wasn't any substitutions. If the target is a FIELD,
+				 * this means no field re-splitting or $0 reconstruction.
+				 * Skip the set_FOO routine if the target is a special variable.
+				 */
+
+				break;
+			} else if (pc->assign_ctxt == Op_K_getline
+				&& TOP()->numbr <= 0.0 	/* top of stack has a number <= 0 */
+			) {
+				/* getline returned EOF or error */
+
+				break;
+			}
+
+			if (pc->opcode == Op_var_assign)
+				pc->assign_var();
+			else
 				pc->field_assign();
 			break;
 
@@ -2260,31 +2275,9 @@ arrayfor:
 				PUSH(r);
 			break;
 
-		case Op_sub_builtin:
-		{
-			/* sub, gsub and gensub */
- 
-			int matches = 0;
-
-			r = do_sub(pc->expr_count, pc->sub_flags, & matches);
+		case Op_sub_builtin:	/* sub, gsub and gensub */
+			r = do_sub(pc->expr_count, pc->sub_flags);
 			PUSH(r);
-
-			if (matches == 0 && (pc->sub_flags & AFTER_ASSIGN) != 0) {
-
-				/* For sub and gsub, must not execute after_assign code;
-				 * If the target is a FIELD, this means no field re-splitting or
-				 * $0 reconstruction. For a special variable as target,
-				 * set_XX routine is not called. 
-				 */
-
-				ni = pc->nexti;
-				assert(ni->opcode == Op_field_assign || ni->opcode == Op_var_assign);
-				if (ni->opcode == Op_field_assign)
-					ni->field_assign = (Func_ptr) 0;
-				else
-					ni->assign_var = (Func_ptr) 0;
-			}
-		}
 			break;
 
 		case Op_K_print:
@@ -2458,6 +2451,7 @@ func_call:
 						JUMPTO((pc + 1)->target_beginfile);
 				}
 			} while (r == NULL);	/* EOF */
+
 			PUSH(r);
 			break;
 
diff --git a/main.c b/main.c
index 120d9ff..657de32 100644
--- a/main.c
+++ b/main.c
@@ -1127,6 +1127,26 @@ is_std_var(const char *var)
 	return FALSE;
 }
 
+
+/* get_spec_varname --- return the name of a special variable
+	with the given assign or update routine.
+*/
+
+const char *
+get_spec_varname(Func_ptr fptr)
+{
+	const struct varinit *vp;
+
+	if (! fptr)
+		return NULL;
+	for (vp = varinit; vp->name != NULL; vp++) {
+		if (vp->assign == fptr || vp->update == fptr)
+			return vp->name;
+	}
+	return NULL;
+}
+
+
 /* arg_assign --- process a command-line assignment */
 
 int