X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pp_ctl.c;h=d20396009dbccac48d3ee869266422eef9885a4d;hb=c86ffc3299ed26fc3616b4d2bb0abdf2e70a0ad1;hp=4cde9f8854ad7435903143340313ff6a2d6d8703;hpb=d8723a6a74b2c12e9d732728dbe717672ab893f2;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/pp_ctl.c b/pp_ctl.c
index 4cde9f8..d203960 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -93,36 +93,84 @@ PP(pp_regcomp)
 	RETURN;
     }
 #endif
+
+#define tryAMAGICregexp(rx)			\
+    STMT_START {				\
+	if (SvROK(rx) && SvAMAGIC(rx)) {	\
+	    SV *sv = AMG_CALLun(rx, regexp);	\
+	    if (sv) {				\
+		if (SvROK(sv))			\
+		    sv = SvRV(sv);		\
+		if (SvTYPE(sv) != SVt_REGEXP)	\
+		    Perl_croak(aTHX_ "Overloaded qr did not return a REGEXP"); \
+		rx = sv;			\
+	    }					\
+	}					\
+    } STMT_END
+	    
+
     if (PL_op->op_flags & OPf_STACKED) {
 	/* multiple args; concatentate them */
 	dMARK; dORIGMARK;
 	tmpstr = PAD_SV(ARGTARG);
 	sv_setpvs(tmpstr, "");
 	while (++MARK <= SP) {
+	    SV *msv = *MARK;
 	    if (PL_amagic_generation) {
 		SV *sv;
-		if ((SvAMAGIC(tmpstr) || SvAMAGIC(*MARK)) &&
-		    (sv = amagic_call(tmpstr, *MARK, concat_amg, AMGf_assign)))
+
+		tryAMAGICregexp(msv);
+
+		if ((SvAMAGIC(tmpstr) || SvAMAGIC(msv)) &&
+		    (sv = amagic_call(tmpstr, msv, concat_amg, AMGf_assign)))
 		{
 		   sv_setsv(tmpstr, sv);
 		   continue;
 		}
 	    }
-	    sv_catsv(tmpstr, *MARK);
+	    sv_catsv(tmpstr, msv);
 	}
     	SvSETMAGIC(tmpstr);
 	SP = ORIGMARK;
     }
-    else
+    else {
 	tmpstr = POPs;
+	tryAMAGICregexp(tmpstr);
+    }
+
+#undef tryAMAGICregexp
 
     if (SvROK(tmpstr)) {
 	SV * const sv = SvRV(tmpstr);
 	if (SvTYPE(sv) == SVt_REGEXP)
 	    re = (REGEXP*) sv;
     }
+    else if (SvTYPE(tmpstr) == SVt_REGEXP)
+	re = (REGEXP*) tmpstr;
+
     if (re) {
-	re = reg_temp_copy(re);
+	/* The match's LHS's get-magic might need to access this op's reg-
+	   exp (as is sometimes the case with $';  see bug 70764).  So we
+	   must call get-magic now before we replace the regexp. Hopeful-
+	   ly this hack can be replaced with the approach described at
+	   http://www.nntp.perl.org/group/perl.perl5.porters/2007/03
+	   /msg122415.html some day. */
+	if(pm->op_type == OP_MATCH) {
+	 SV *lhs;
+	 const bool was_tainted = PL_tainted;
+	 if (pm->op_flags & OPf_STACKED)
+	    lhs = TOPs;
+	 else if (pm->op_private & OPpTARGET_MY)
+	    lhs = PAD_SV(pm->op_targ);
+	 else lhs = DEFSV;
+	 SvGETMAGIC(lhs);
+	 /* Restore the previous value of PL_tainted (which may have been
+	    modified by get-magic), to avoid incorrectly setting the
+	    RXf_TAINTED flag further down. */
+	 PL_tainted = was_tainted;
+	}
+
+	re = reg_temp_copy(NULL, re);
 	ReREFCNT_dec(PM_GETRE(pm));
 	PM_SETRE(pm, re);
     }
@@ -216,6 +264,9 @@ PP(pp_substcont)
     register REGEXP * const rx = cx->sb_rx;
     SV *nsv = NULL;
     REGEXP *old = PM_GETRE(pm);
+
+    PERL_ASYNC_CHECK();
+
     if(old != rx) {
 	if(old)
 	    ReREFCNT_dec(old);
@@ -230,16 +281,21 @@ PP(pp_substcont)
 	if (cx->sb_iters > cx->sb_maxiters)
 	    DIE(aTHX_ "Substitution loop");
 
+	SvGETMAGIC(TOPs); /* possibly clear taint on $1 etc: #67962 */
+
 	if (!(cx->sb_rxtainted & 2) && SvTAINTED(TOPs))
 	    cx->sb_rxtainted |= 2;
-	sv_catsv(dstr, POPs);
+	sv_catsv_nomg(dstr, POPs);
+	/* XXX: adjust for positive offsets of \G for instance s/(.)\G//g with positive pos() */
+	s -= RX_GOFS(rx);
 
 	/* Are we done */
-	if (CxONCE(cx) || !CALLREGEXEC(rx, s, cx->sb_strend, orig,
-				     s == m, cx->sb_targ, NULL,
-				     ((cx->sb_rflags & REXEC_COPY_STR)
-				      ? (REXEC_IGNOREPOS|REXEC_NOT_FIRST)
-				      : (REXEC_COPY_STR|REXEC_IGNOREPOS|REXEC_NOT_FIRST))))
+	if (CxONCE(cx) || s < orig ||
+		!CALLREGEXEC(rx, s, cx->sb_strend, orig,
+			     (s == m) + RX_GOFS(rx), cx->sb_targ, NULL,
+			     ((cx->sb_rflags & REXEC_COPY_STR)
+			      ? (REXEC_IGNOREPOS|REXEC_NOT_FIRST)
+			      : (REXEC_COPY_STR|REXEC_IGNOREPOS|REXEC_NOT_FIRST))))
 	{
 	    SV * const targ = cx->sb_targ;
 
@@ -532,8 +588,7 @@ PP(pp_formline)
 		sv = *++MARK;
 	    else {
 		sv = &PL_sv_no;
-		if (ckWARN(WARN_SYNTAX))
-		    Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Not enough format arguments");
+		Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX), "Not enough format arguments");
 	    }
 	    break;
 
@@ -901,11 +956,6 @@ PP(pp_formline)
 		    *t = '\0';
 		    SvCUR_set(PL_formtarget, t - SvPVX_const(PL_formtarget));
 		    lines += FmLINES(PL_formtarget);
-		    if (lines == 200) {
-			arg = t - linemark;
-			if (strnEQ(linemark, linemark - arg, arg))
-			    DIE(aTHX_ "Runaway format");
-		    }
 		    if (targ_is_utf8)
 			SvUTF8_on(PL_formtarget);
 		    FmLINES(PL_formtarget) = lines;
@@ -972,14 +1022,14 @@ PP(pp_grepstart)
     PL_stack_sp = PL_stack_base + *PL_markstack_ptr + 1;
     pp_pushmark();				/* push dst */
     pp_pushmark();				/* push src */
-    ENTER;					/* enter outer scope */
+    ENTER_with_name("grep");					/* enter outer scope */
 
     SAVETMPS;
     if (PL_op->op_private & OPpGREP_LEX)
 	SAVESPTR(PAD_SVl(PL_op->op_targ));
     else
 	SAVE_DEFSV;
-    ENTER;					/* enter inner scope */
+    ENTER_with_name("grep_item");					/* enter inner scope */
     SAVEVPTR(PL_curpm);
 
     src = PL_stack_base[*PL_markstack_ptr];
@@ -1060,13 +1110,13 @@ PP(pp_mapwhile)
 	    }
 	}
     }
-    LEAVE;					/* exit inner scope */
+    LEAVE_with_name("grep_item");					/* exit inner scope */
 
     /* All done yet? */
     if (PL_markstack_ptr[-1] > *PL_markstack_ptr) {
 
 	(void)POPMARK;				/* pop top */
-	LEAVE;					/* exit outer scope */
+	LEAVE_with_name("grep");					/* exit outer scope */
 	(void)POPMARK;				/* pop src */
 	items = --*PL_markstack_ptr - PL_markstack_ptr[-1];
 	(void)POPMARK;				/* pop dst */
@@ -1089,7 +1139,7 @@ PP(pp_mapwhile)
     else {
 	SV *src;
 
-	ENTER;					/* enter inner scope */
+	ENTER_with_name("grep_item");					/* enter inner scope */
 	SAVEVPTR(PL_curpm);
 
 	/* set $_ to the new source item */
@@ -1280,9 +1330,8 @@ S_dopoptolabel(pTHX_ const char *label)
 	case CXt_FORMAT:
 	case CXt_EVAL:
 	case CXt_NULL:
-	    if (ckWARN(WARN_EXITING))
-		Perl_warner(aTHX_ packWARN(WARN_EXITING), "Exiting %s via %s",
-			context_name[CxTYPE(cx)], OP_NAME(PL_op));
+	    Perl_ck_warner(aTHX_ packWARN(WARN_EXITING), "Exiting %s via %s",
+			   context_name[CxTYPE(cx)], OP_NAME(PL_op));
 	    if (CxTYPE(cx) == CXt_NULL)
 		return -1;
 	    break;
@@ -1290,13 +1339,16 @@ S_dopoptolabel(pTHX_ const char *label)
 	case CXt_LOOP_LAZYSV:
 	case CXt_LOOP_FOR:
 	case CXt_LOOP_PLAIN:
-	    if ( !CxLABEL(cx) || strNE(label, CxLABEL(cx)) ) {
-		DEBUG_l(Perl_deb(aTHX_ "(Skipping label #%ld %s)\n",
-			(long)i, CxLABEL(cx)));
+	  {
+	    const char *cx_label = CxLABEL(cx);
+	    if (!cx_label || strNE(label, cx_label) ) {
+		DEBUG_l(Perl_deb(aTHX_ "(poptolabel(): skipping label at cx=%ld %s)\n",
+			(long)i, cx_label));
 		continue;
 	    }
-	    DEBUG_l( Perl_deb(aTHX_ "(Found label #%ld %s)\n", (long)i, label));
+	    DEBUG_l( Perl_deb(aTHX_ "(poptolabel(): found label at cx=%ld %s)\n", (long)i, label));
 	    return i;
+	  }
 	}
     }
     return i;
@@ -1363,7 +1415,7 @@ S_dopoptosub_at(pTHX_ const PERL_CONTEXT *cxstk, I32 startingblock)
 	case CXt_EVAL:
 	case CXt_SUB:
 	case CXt_FORMAT:
-	    DEBUG_l( Perl_deb(aTHX_ "(Found sub #%ld)\n", (long)i));
+	    DEBUG_l( Perl_deb(aTHX_ "(dopoptosub_at(): found sub at cx=%ld)\n", (long)i));
 	    return i;
 	}
     }
@@ -1381,7 +1433,7 @@ S_dopoptoeval(pTHX_ I32 startingblock)
 	default:
 	    continue;
 	case CXt_EVAL:
-	    DEBUG_l( Perl_deb(aTHX_ "(Found eval #%ld)\n", (long)i));
+	    DEBUG_l( Perl_deb(aTHX_ "(dopoptoeval(): found eval at cx=%ld)\n", (long)i));
 	    return i;
 	}
     }
@@ -1401,9 +1453,8 @@ S_dopoptoloop(pTHX_ I32 startingblock)
 	case CXt_FORMAT:
 	case CXt_EVAL:
 	case CXt_NULL:
-	    if (ckWARN(WARN_EXITING))
-		Perl_warner(aTHX_ packWARN(WARN_EXITING), "Exiting %s via %s",
-			context_name[CxTYPE(cx)], OP_NAME(PL_op));
+	    Perl_ck_warner(aTHX_ packWARN(WARN_EXITING), "Exiting %s via %s",
+			   context_name[CxTYPE(cx)], OP_NAME(PL_op));
 	    if ((CxTYPE(cx)) == CXt_NULL)
 		return -1;
 	    break;
@@ -1411,7 +1462,7 @@ S_dopoptoloop(pTHX_ I32 startingblock)
 	case CXt_LOOP_LAZYSV:
 	case CXt_LOOP_FOR:
 	case CXt_LOOP_PLAIN:
-	    DEBUG_l( Perl_deb(aTHX_ "(Found loop #%ld)\n", (long)i));
+	    DEBUG_l( Perl_deb(aTHX_ "(dopoptoloop(): found loop at cx=%ld)\n", (long)i));
 	    return i;
 	}
     }
@@ -1429,7 +1480,7 @@ S_dopoptogiven(pTHX_ I32 startingblock)
 	default:
 	    continue;
 	case CXt_GIVEN:
-	    DEBUG_l( Perl_deb(aTHX_ "(Found given #%ld)\n", (long)i));
+	    DEBUG_l( Perl_deb(aTHX_ "(dopoptogiven(): found given at cx=%ld)\n", (long)i));
 	    return i;
 	case CXt_LOOP_PLAIN:
 	    assert(!CxFOREACHDEF(cx));
@@ -1438,7 +1489,7 @@ S_dopoptogiven(pTHX_ I32 startingblock)
 	case CXt_LOOP_LAZYSV:
 	case CXt_LOOP_FOR:
 	    if (CxFOREACHDEF(cx)) {
-		DEBUG_l( Perl_deb(aTHX_ "(Found foreach #%ld)\n", (long)i));
+		DEBUG_l( Perl_deb(aTHX_ "(dopoptogiven(): found foreach at cx=%ld)\n", (long)i));
 		return i;
 	    }
 	}
@@ -1457,7 +1508,7 @@ S_dopoptowhen(pTHX_ I32 startingblock)
 	default:
 	    continue;
 	case CXt_WHEN:
-	    DEBUG_l( Perl_deb(aTHX_ "(Found when #%ld)\n", (long)i));
+	    DEBUG_l( Perl_deb(aTHX_ "(dopoptowhen(): found when at cx=%ld)\n", (long)i));
 	    return i;
 	}
     }
@@ -1473,8 +1524,7 @@ Perl_dounwind(pTHX_ I32 cxix)
     while (cxstack_ix > cxix) {
 	SV *sv;
         register PERL_CONTEXT *cx = &cxstack[cxstack_ix];
-	DEBUG_l(PerlIO_printf(Perl_debug_log, "Unwinding block %ld, type %s\n",
-			      (long) cxstack_ix, PL_block_type[CxTYPE(cx)]));
+	DEBUG_CX("UNWIND");						\
 	/* Note: we don't need to restore the base context info till the end. */
 	switch (CxTYPE(cx)) {
 	case CXt_SUBST:
@@ -1521,45 +1571,18 @@ Perl_qerror(pTHX_ SV *err)
 	++PL_parser->error_count;
 }
 
-OP *
-Perl_die_where(pTHX_ const char *message, STRLEN msglen)
+void
+Perl_die_unwind(pTHX_ SV *msv)
 {
     dVAR;
+    SV *exceptsv = sv_mortalcopy(msv);
+    U8 in_eval = PL_in_eval;
+    PERL_ARGS_ASSERT_DIE_UNWIND;
 
-    if (PL_in_eval) {
+    if (in_eval) {
 	I32 cxix;
 	I32 gimme;
 
-	if (message) {
-	    if (PL_in_eval & EVAL_KEEPERR) {
-                static const char prefix[] = "\t(in cleanup) ";
-		SV * const err = ERRSV;
-		const char *e = NULL;
-		if (!SvPOK(err))
-		    sv_setpvs(err,"");
-		else if (SvCUR(err) >= sizeof(prefix)+msglen-1) {
-		    STRLEN len;
-		    e = SvPV_const(err, len);
-		    e += len - msglen;
-		    if (*e != *message || strNE(e,message))
-			e = NULL;
-		}
-		if (!e) {
-		    SvGROW(err, SvCUR(err)+sizeof(prefix)+msglen);
-		    sv_catpvn(err, prefix, sizeof(prefix)-1);
-		    sv_catpvn(err, message, msglen);
-		    if (ckWARN(WARN_MISC)) {
-			const STRLEN start = SvCUR(err)-msglen-sizeof(prefix)+1;
-			Perl_warner(aTHX_ packWARN(WARN_MISC), "%s",
-				SvPVX_const(err)+start);
-		    }
-		}
-	    }
-	    else {
-		sv_setpvn(ERRSV, message, msglen);
-	    }
-	}
-
 	while ((cxix = dopoptoeval(cxstack_ix)) < 0
 	       && PL_curstackinfo->si_prev)
 	{
@@ -1569,6 +1592,7 @@ Perl_die_where(pTHX_ const char *message, STRLEN msglen)
 
 	if (cxix >= 0) {
 	    I32 optype;
+	    SV *namesv;
 	    register PERL_CONTEXT *cx;
 	    SV **newsp;
 
@@ -1577,13 +1601,14 @@ Perl_die_where(pTHX_ const char *message, STRLEN msglen)
 
 	    POPBLOCK(cx,PL_curpm);
 	    if (CxTYPE(cx) != CXt_EVAL) {
-		if (!message)
-		    message = SvPVx_const(ERRSV, msglen);
+		STRLEN msglen;
+		const char* message = SvPVx_const(exceptsv, msglen);
 		PerlIO_write(Perl_error_log, (const char *)"panic: die ", 11);
 		PerlIO_write(Perl_error_log, message, msglen);
 		my_exit(1);
 	    }
 	    POPEVAL(cx);
+	    namesv = cx->blk_eval.old_namesv;
 
 	    if (gimme == G_SCALAR)
 		*++newsp = &PL_sv_undef;
@@ -1598,24 +1623,35 @@ Perl_die_where(pTHX_ const char *message, STRLEN msglen)
 	    PL_curcop = cx->blk_oldcop;
 
 	    if (optype == OP_REQUIRE) {
-                const char* const msg = SvPVx_nolen_const(ERRSV);
-		SV * const nsv = cx->blk_eval.old_namesv;
-                (void)hv_store(GvHVn(PL_incgv), SvPVX_const(nsv), SvCUR(nsv),
+                const char* const msg = SvPVx_nolen_const(exceptsv);
+                (void)hv_store(GvHVn(PL_incgv),
+                               SvPVX_const(namesv), SvCUR(namesv),
                                &PL_sv_undef, 0);
+		/* note that unlike pp_entereval, pp_require isn't
+		 * supposed to trap errors. So now that we've popped the
+		 * EVAL that pp_require pushed, and processed the error
+		 * message, rethrow the error */
 		DIE(aTHX_ "%sCompilation failed in require",
 		    *msg ? msg : "Unknown error\n");
 	    }
+	    if (in_eval & EVAL_KEEPERR) {
+		Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "\t(in cleanup) %s",
+			       SvPV_nolen_const(exceptsv));
+	    }
+	    else {
+		sv_setsv(ERRSV, exceptsv);
+	    }
 	    assert(CxTYPE(cx) == CXt_EVAL);
-	    return cx->blk_eval.retop;
+	    PL_restartjmpenv = cx->blk_eval.cur_top_env;
+	    PL_restartop = cx->blk_eval.retop;
+	    JMPENV_JUMP(3);
+	    /* NOTREACHED */
 	}
     }
-    if (!message)
-	message = SvPVx_const(ERRSV, msglen);
 
-    write_to_stderr(message, msglen);
+    write_to_stderr(exceptsv);
     my_failure_exit();
     /* NOTREACHED */
-    return 0;
 }
 
 PP(pp_xor)
@@ -1816,6 +1852,8 @@ PP(pp_dbstate)
     PL_stack_sp = PL_stack_base + cxstack[cxstack_ix].blk_oldsp;
     FREETMPS;
 
+    PERL_ASYNC_CHECK();
+
     if (PL_op->op_flags & OPf_SPECIAL /* breakpoint */
 	    || SvIV(PL_DBsingle) || SvIV(PL_DBsignal) || SvIV(PL_DBtrace))
     {
@@ -1876,7 +1914,7 @@ PP(pp_enteriter)
     PAD *iterdata;
 #endif
 
-    ENTER;
+    ENTER_with_name("loop1");
     SAVETMPS;
 
     if (PL_op->op_targ) {
@@ -1905,7 +1943,7 @@ PP(pp_enteriter)
     if (PL_op->op_private & OPpITER_DEF)
 	cxtype |= CXp_FOR_DEF;
 
-    ENTER;
+    ENTER_with_name("loop2");
 
     PUSHBLOCK(cx, cxtype, SP);
 #ifdef USE_ITHREADS
@@ -2002,9 +2040,9 @@ PP(pp_enterloop)
     register PERL_CONTEXT *cx;
     const I32 gimme = GIMME_V;
 
-    ENTER;
+    ENTER_with_name("loop1");
     SAVETMPS;
-    ENTER;
+    ENTER_with_name("loop2");
 
     PUSHBLOCK(cx, CXt_LOOP_PLAIN, SP);
     PUSHLOOP_PLAIN(cx, SP);
@@ -2047,8 +2085,8 @@ PP(pp_leaveloop)
     POPLOOP(cx);	/* Stack values are safe: release loop vars ... */
     PL_curpm = newpm;	/* ... and pop $1 et al */
 
-    LEAVE;
-    LEAVE;
+    LEAVE_with_name("loop2");
+    LEAVE_with_name("loop1");
 
     return NORMAL;
 }
@@ -2063,8 +2101,9 @@ PP(pp_return)
     SV **newsp;
     PMOP *newpm;
     I32 optype = 0;
+    SV *namesv;
     SV *sv;
-    OP *retop;
+    OP *retop = NULL;
 
     const I32 cxix = dopoptosub(cxstack_ix);
 
@@ -2105,6 +2144,7 @@ PP(pp_return)
 	if (!(PL_in_eval & EVAL_KEEPERR))
 	    clear_errsv = TRUE;
 	POPEVAL(cx);
+	namesv = cx->blk_eval.old_namesv;
 	retop = cx->blk_eval.retop;
 	if (CxTRYBLOCK(cx))
 	    break;
@@ -2113,9 +2153,10 @@ PP(pp_return)
 	    (MARK == SP || (gimme == G_SCALAR && !SvTRUE(*SP))) )
 	{
 	    /* Unassume the success we assumed earlier. */
-	    SV * const nsv = cx->blk_eval.old_namesv;
-	    (void)hv_delete(GvHVn(PL_incgv), SvPVX_const(nsv), SvCUR(nsv), G_DISCARD);
-	    DIE(aTHX_ "%"SVf" did not return a true value", SVfARG(nsv));
+	    (void)hv_delete(GvHVn(PL_incgv),
+			    SvPVX_const(namesv), SvCUR(namesv),
+			    G_DISCARD);
+	    DIE(aTHX_ "%"SVf" did not return a true value", SVfARG(namesv));
 	}
 	break;
     case CXt_FORMAT:
@@ -2186,7 +2227,7 @@ PP(pp_last)
     I32 pop2 = 0;
     I32 gimme;
     I32 optype;
-    OP *nextop;
+    OP *nextop = NULL;
     SV **newsp;
     PMOP *newpm;
     SV **mark;
@@ -2368,9 +2409,11 @@ S_dofindlabel(pTHX_ OP *o, const char *label, OP **opstack, OP **oplimit)
 	OP *kid;
 	/* First try all the kids at this level, since that's likeliest. */
 	for (kid = cUNOPo->op_first; kid; kid = kid->op_sibling) {
-	    if ((kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE) &&
-		    CopLABEL(kCOP) && strEQ(CopLABEL(kCOP), label))
-		return kid;
+	    if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE) {
+		const char *kid_label = CopLABEL(kCOP);
+		if (kid_label && strEQ(kid_label, label))
+		    return kid;
+	    }
 	}
 	for (kid = cUNOPo->op_first; kid; kid = kid->op_sibling) {
 	    if (kid == PL_lastgotoprobe)
@@ -2596,6 +2639,8 @@ PP(pp_goto)
     else
 	label = cPVOP->op_pv;
 
+    PERL_ASYNC_CHECK();
+
     if (label && *label) {
 	OP *gotoprobe = NULL;
 	bool leaving_eval = FALSE;
@@ -2673,6 +2718,12 @@ PP(pp_goto)
                     DIE(aTHX_ "Can't \"goto\" into the middle of a foreach loop");
 	}
 
+	if (*enterops && enterops[1]) {
+	    I32 i = enterops[1]->op_type == OP_ENTER && in_block ? 2 : 1;
+	    if (enterops[i])
+		deprecate("\"goto\" to jump into a construct");
+	}
+
 	/* pop unwanted frames */
 
 	if (ix < cxstack_ix) {
@@ -2774,6 +2825,20 @@ S_save_lines(pTHX_ AV *array, SV *sv)
     }
 }
 
+/*
+=for apidoc docatch
+
+Check for the cases 0 or 3 of cur_env.je_ret, only used inside an eval context.
+
+0 is used as continue inside eval,
+
+3 is used for a die caught by an inner eval - continue inner loop
+
+See cop.h: je_mustcatch, when set at any runlevel to TRUE, means eval ops must
+establish a local jmpenv to handle exception traps.
+
+=cut
+*/
 STATIC OP *
 S_docatch(pTHX_ OP *o)
 {
@@ -2798,17 +2863,8 @@ S_docatch(pTHX_ OP *o)
 	break;
     case 3:
 	/* die caught by an inner eval - continue inner loop */
-
-	/* NB XXX we rely on the old popped CxEVAL still being at the top
-	 * of the stack; the way die_where() currently works, this
-	 * assumption is valid. In theory The cur_top_env value should be
-	 * returned in another global, the way retop (aka PL_restartop)
-	 * is. */
-	assert(CxTYPE(&cxstack[cxstack_ix+1]) == CXt_EVAL);
-
-	if (PL_restartop
-	    && cxstack[cxstack_ix+1].blk_eval.cur_top_env == PL_top_env)
-	{
+	if (PL_restartop && PL_restartjmpenv == PL_top_env) {
+	    PL_restartjmpenv = NULL;
 	    PL_op = PL_restartop;
 	    PL_restartop = 0;
 	    goto redo_body;
@@ -2825,13 +2881,20 @@ S_docatch(pTHX_ OP *o)
     return NULL;
 }
 
+/* James Bond: Do you expect me to talk?
+   Auric Goldfinger: No, Mr. Bond. I expect you to die.
+
+   This code is an ugly hack, doesn't work with lexicals in subroutines that are
+   called more than once, and is only used by regcomp.c, for (?{}) blocks.
+
+   Currently it is not used outside the core code. Best if it stays that way.
+*/
 OP *
 Perl_sv_compile_2op(pTHX_ SV *sv, OP** startop, const char *code, PAD** padp)
 /* sv Text to convert to OP tree. */
 /* startop op_free() this to undo. */
 /* code Short string id of the caller. */
 {
-    /* FIXME - how much of this code is common with pp_entereval?  */
     dVAR; dSP;				/* Make POPBLOCK work. */
     PERL_CONTEXT *cx;
     SV **newsp;
@@ -2847,7 +2910,7 @@ Perl_sv_compile_2op(pTHX_ SV *sv, OP** startop, const char *code, PAD** padp)
 
     PERL_ARGS_ASSERT_SV_COMPILE_2OP;
 
-    ENTER;
+    ENTER_with_name("eval");
     lex_start(sv, NULL, FALSE);
     SAVETMPS;
     /* switch to eval mode */
@@ -2908,7 +2971,7 @@ Perl_sv_compile_2op(pTHX_ SV *sv, OP** startop, const char *code, PAD** padp)
     lex_end();
     /* XXX DAPM do this properly one year */
     *padp = MUTABLE_AV(SvREFCNT_inc_simple(PL_comppad));
-    LEAVE;
+    LEAVE_with_name("eval");
     if (IN_PERL_COMPILETIME)
 	CopHINTS_set(&PL_compiling, PL_hints);
 #ifdef OP_IN_REGISTER
@@ -2962,6 +3025,35 @@ Perl_find_runcv(pTHX_ U32 *db_seqp)
 }
 
 
+/* Run yyparse() in a setjmp wrapper. Returns:
+ *   0: yyparse() successful
+ *   1: yyparse() failed
+ *   3: yyparse() died
+ */
+STATIC int
+S_try_yyparse(pTHX)
+{
+    int ret;
+    dJMPENV;
+
+    assert(CxTYPE(&cxstack[cxstack_ix]) == CXt_EVAL);
+    JMPENV_PUSH(ret);
+    switch (ret) {
+    case 0:
+	ret = yyparse() ? 1 : 0;
+	break;
+    case 3:
+	break;
+    default:
+	JMPENV_POP;
+	JMPENV_JUMP(ret);
+	/* NOTREACHED */
+    }
+    JMPENV_POP;
+    return ret;
+}
+
+
 /* Compile a require/do, an eval '', or a /(?{...})/.
  * In the last case, startop is non-null, and contains the address of
  * a pointer that should be set to the just-compiled code.
@@ -2976,8 +3068,10 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
 {
     dVAR; dSP;
     OP * const saveop = PL_op;
+    bool in_require = (saveop && saveop->op_type == OP_REQUIRE);
+    int yystatus;
 
-    PL_in_eval = ((saveop && saveop->op_type == OP_REQUIRE)
+    PL_in_eval = (in_require
 		  ? (EVAL_INREQUIRE | (PL_in_eval & EVAL_INEVAL))
 		  : EVAL_INEVAL);
 
@@ -3029,36 +3123,61 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
 	PL_in_eval |= EVAL_KEEPERR;
     else
 	CLEAR_ERRSV();
-    if (yyparse() || PL_parser->error_count || !PL_eval_root) {
+
+    /* note that yyparse() may raise an exception, e.g. C<BEGIN{die}>,
+     * so honour CATCH_GET and trap it here if necessary */
+
+    yystatus = (!in_require && CATCH_GET) ? S_try_yyparse(aTHX) : yyparse();
+
+    if (yystatus || PL_parser->error_count || !PL_eval_root) {
 	SV **newsp;			/* Used by POPBLOCK. */
-	PERL_CONTEXT *cx = &cxstack[cxstack_ix];
-	I32 optype = 0;			/* Might be reset by POPEVAL. */
+	PERL_CONTEXT *cx = NULL;
+	I32 optype;			/* Used by POPEVAL. */
+	SV *namesv = NULL;
 	const char *msg;
 
+	PERL_UNUSED_VAR(newsp);
+	PERL_UNUSED_VAR(optype);
+
+	/* note that if yystatus == 3, then the EVAL CX block has already
+	 * been popped, and various vars restored */
 	PL_op = saveop;
-	if (PL_eval_root) {
-	    op_free(PL_eval_root);
-	    PL_eval_root = NULL;
-	}
-	SP = PL_stack_base + POPMARK;		/* pop original mark */
-	if (!startop) {
-	    POPBLOCK(cx,PL_curpm);
-	    POPEVAL(cx);
+	if (yystatus != 3) {
+	    if (PL_eval_root) {
+		op_free(PL_eval_root);
+		PL_eval_root = NULL;
+	    }
+	    SP = PL_stack_base + POPMARK;	/* pop original mark */
+	    if (!startop) {
+		POPBLOCK(cx,PL_curpm);
+		POPEVAL(cx);
+		namesv = cx->blk_eval.old_namesv;
+	    }
 	}
 	lex_end();
-	LEAVE; /* pp_entereval knows about this LEAVE.  */
+	if (yystatus != 3)
+	    LEAVE_with_name("eval"); /* pp_entereval knows about this LEAVE.  */
 
 	msg = SvPVx_nolen_const(ERRSV);
-	if (optype == OP_REQUIRE) {
-	    const SV * const nsv = cx->blk_eval.old_namesv;
-	    (void)hv_store(GvHVn(PL_incgv), SvPVX_const(nsv), SvCUR(nsv),
-                          &PL_sv_undef, 0);
+	if (in_require) {
+	    if (!cx) {
+		/* If cx is still NULL, it means that we didn't go in the
+		 * POPEVAL branch. */
+		cx = &cxstack[cxstack_ix];
+		assert(CxTYPE(cx) == CXt_EVAL);
+		namesv = cx->blk_eval.old_namesv;
+	    }
+	    (void)hv_store(GvHVn(PL_incgv),
+			   SvPVX_const(namesv), SvCUR(namesv),
+			   &PL_sv_undef, 0);
 	    Perl_croak(aTHX_ "%sCompilation failed in require",
 		       *msg ? msg : "Unknown error\n");
 	}
 	else if (startop) {
-	    POPBLOCK(cx,PL_curpm);
-	    POPEVAL(cx);
+	    if (yystatus != 3) {
+		POPBLOCK(cx,PL_curpm);
+		POPEVAL(cx);
+	    }
 	    Perl_croak(aTHX_ "%sCompilation failed in regexp",
 		       (*msg ? msg : "Unknown error\n"));
 	}
@@ -3067,7 +3186,6 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
 	        sv_setpvs(ERRSV, "Compilation error");
 	    }
 	}
-	PERL_UNUSED_VAR(newsp);
 	PUSHs(&PL_sv_undef);
 	PUTBACK;
 	return FALSE;
@@ -3079,14 +3197,8 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
 	SAVEFREEOP(PL_eval_root);
 
     /* Set the context for this new optree.
-     * If the last op is an OP_REQUIRE, force scalar context.
-     * Otherwise, propagate the context from the eval(). */
-    if (PL_eval_root->op_type == OP_LEAVEEVAL
-	    && cUNOPx(PL_eval_root)->op_first->op_type == OP_LINESEQ
-	    && cLISTOPx(cUNOPx(PL_eval_root)->op_first)->op_last->op_type
-	    == OP_REQUIRE)
-	scalar(PL_eval_root);
-    else if ((gimme & G_WANT) == G_VOID)
+     * Propagate the context from the eval(). */
+    if ((gimme & G_WANT) == G_VOID)
 	scalarvoid(PL_eval_root);
     else if ((gimme & G_WANT) == G_ARRAY)
 	list(PL_eval_root);
@@ -3225,21 +3337,21 @@ PP(pp_require)
 			SVfARG(vnormal(PL_patchlevel)));
 		}
 		else { /* probably 'use 5.10' or 'use 5.8' */
-		    SV * hintsv = newSV(0);
+		    SV *hintsv;
 		    I32 second = 0;
 
 		    if (av_len(lav)>=1) 
 			second = SvIV(*av_fetch(lav,1,0));
 
 		    second /= second >= 600  ? 100 : 10;
-		    hintsv = Perl_newSVpvf(aTHX_ "v%d.%d.%d",
-		    	(int)first, (int)second,0);
+		    hintsv = Perl_newSVpvf(aTHX_ "v%d.%d.0",
+					   (int)first, (int)second);
 		    upg_version(hintsv, TRUE);
 
 		    DIE(aTHX_ "Perl %"SVf" required (did you mean %"SVf"?)"
 		    	"--this is only %"SVf", stopped",
 			SVfARG(vnormal(req)),
-			SVfARG(vnormal(hintsv)),
+			SVfARG(vnormal(sv_2mortal(hintsv))),
 			SVfARG(vnormal(PL_patchlevel)));
 		}
 	    }
@@ -3252,9 +3364,9 @@ PP(pp_require)
 		vcmp(sv, sv_2mortal(upg_version(newSVnv(5.009005), FALSE))) >= 0) {
 	    SV *const importsv = vnormal(sv);
 	    *SvPVX_mutable(importsv) = ':';
-	    ENTER;
+	    ENTER_with_name("load_feature");
 	    Perl_load_module(aTHX_ 0, newSVpvs("feature"), NULL, importsv, NULL);
-	    LEAVE;
+	    LEAVE_with_name("load_feature");
 	}
 	/* If a version >= 5.11.0 is requested, strictures are on by default! */
 	if (PL_compcv &&
@@ -3337,7 +3449,7 @@ PP(pp_require)
 		    tryname = SvPVX_const(namesv);
 		    tryrsfp = NULL;
 
-		    ENTER;
+		    ENTER_with_name("call_INC");
 		    SAVETMPS;
 		    EXTEND(SP, 2);
 
@@ -3415,7 +3527,7 @@ PP(pp_require)
 
 		    PUTBACK;
 		    FREETMPS;
-		    LEAVE;
+		    LEAVE_with_name("call_INC");
 
 		    if (tryrsfp) {
 			hook_sv = dirsv;
@@ -3562,7 +3674,7 @@ PP(pp_require)
 			   unixname, unixlen, SvREFCNT_inc_simple(hook_sv), 0 );
     }
 
-    ENTER;
+    ENTER_with_name("eval");
     SAVETMPS;
     lex_start(NULL, tryrsfp, TRUE);
 
@@ -3579,11 +3691,14 @@ PP(pp_require)
         PL_compiling.cop_warnings = pWARN_STD ;
 
     if (filter_sub || filter_cache) {
-	SV * const datasv = filter_add(S_run_user_filter, NULL);
+	/* We can use the SvPV of the filter PVIO itself as our cache, rather
+	   than hanging another SV from it. In turn, filter_add() optionally
+	   takes the SV to use as the filter (or creates a new SV if passed
+	   NULL), so simply pass in whatever value filter_cache has.  */
+	SV * const datasv = filter_add(S_run_user_filter, filter_cache);
 	IoLINES(datasv) = filter_has_file;
 	IoTOP_GV(datasv) = MUTABLE_GV(filter_state);
 	IoBOTTOM_GV(datasv) = MUTABLE_GV(filter_sub);
-	IoFMT_GV(datasv) = MUTABLE_GV(filter_cache);
     }
 
     /* switch to eval mode */
@@ -3646,7 +3761,7 @@ PP(pp_entereval)
     TAINT_IF(SvTAINTED(sv));
     TAINT_PROPER("eval");
 
-    ENTER;
+    ENTER_with_name("eval");
     lex_start(sv, NULL, FALSE);
     SAVETMPS;
 
@@ -3683,7 +3798,18 @@ PP(pp_entereval)
     if (PL_compiling.cop_hints_hash) {
 	Perl_refcounted_he_free(aTHX_ PL_compiling.cop_hints_hash);
     }
-    PL_compiling.cop_hints_hash = PL_curcop->cop_hints_hash;
+    if (Perl_fetch_cop_label(aTHX_ PL_curcop->cop_hints_hash, NULL, NULL)) {
+	/* The label, if present, is the first entry on the chain. So rather
+	   than writing a blank label in front of it (which involves an
+	   allocation), just use the next entry in the chain.  */
+	PL_compiling.cop_hints_hash
+	    = PL_curcop->cop_hints_hash->refcounted_he_next;
+	/* Check the assumption that this removed the label.  */
+	assert(Perl_fetch_cop_label(aTHX_ PL_compiling.cop_hints_hash, NULL,
+				    NULL) == NULL);
+    }
+    else
+	PL_compiling.cop_hints_hash = PL_curcop->cop_hints_hash;
     if (PL_compiling.cop_hints_hash) {
 	HINTS_REFCNT_LOCK;
 	PL_compiling.cop_hints_hash->refcounted_he_refcnt++;
@@ -3741,9 +3867,11 @@ PP(pp_leaveeval)
     OP *retop;
     const U8 save_flags = PL_op -> op_flags;
     I32 optype;
+    SV *namesv;
 
     POPBLOCK(cx,newpm);
     POPEVAL(cx);
+    namesv = cx->blk_eval.old_namesv;
     retop = cx->blk_eval.retop;
 
     TAINT_NOT;
@@ -3784,13 +3912,15 @@ PP(pp_leaveeval)
 	!(gimme == G_SCALAR ? SvTRUE(*SP) : SP > newsp))
     {
 	/* Unassume the success we assumed earlier. */
-	SV * const nsv = cx->blk_eval.old_namesv;
-	(void)hv_delete(GvHVn(PL_incgv), SvPVX_const(nsv), SvCUR(nsv), G_DISCARD);
-	retop = Perl_die(aTHX_ "%"SVf" did not return a true value", SVfARG(nsv));
-	/* die_where() did LEAVE, or we won't be here */
+	(void)hv_delete(GvHVn(PL_incgv),
+			SvPVX_const(namesv), SvCUR(namesv),
+			G_DISCARD);
+	retop = Perl_die(aTHX_ "%"SVf" did not return a true value",
+			       SVfARG(namesv));
+	/* die_unwind() did LEAVE, or we won't be here */
     }
     else {
-	LEAVE;
+	LEAVE_with_name("eval");
 	if (!(save_flags & OPf_SPECIAL)) {
 	    CLEAR_ERRSV();
 	}
@@ -3813,7 +3943,7 @@ Perl_delete_eval_scope(pTHX)
     POPBLOCK(cx,newpm);
     POPEVAL(cx);
     PL_curpm = newpm;
-    LEAVE;
+    LEAVE_with_name("eval_scope");
     PERL_UNUSED_VAR(newsp);
     PERL_UNUSED_VAR(gimme);
     PERL_UNUSED_VAR(optype);
@@ -3827,7 +3957,7 @@ Perl_create_eval_scope(pTHX_ U32 flags)
     PERL_CONTEXT *cx;
     const I32 gimme = GIMME_V;
 	
-    ENTER;
+    ENTER_with_name("eval_scope");
     SAVETMPS;
 
     PUSHBLOCK(cx, (CXt_EVAL|CXp_TRYBLOCK), PL_stack_sp);
@@ -3895,7 +4025,7 @@ PP(pp_leavetry)
     }
     PL_curpm = newpm;	/* Don't pop $1 et al till now */
 
-    LEAVE;
+    LEAVE_with_name("eval_scope");
     CLEAR_ERRSV();
     RETURN;
 }
@@ -3906,7 +4036,7 @@ PP(pp_entergiven)
     register PERL_CONTEXT *cx;
     const I32 gimme = GIMME_V;
     
-    ENTER;
+    ENTER_with_name("given");
     SAVETMPS;
 
     sv_setsv(PAD_SV(PL_op->op_targ), POPs);
@@ -3934,7 +4064,7 @@ PP(pp_leavegiven)
 
     PL_curpm = newpm;   /* pop $1 et al */
 
-    LEAVE;
+    LEAVE_with_name("given");
 
     return NORMAL;
 }
@@ -3951,7 +4081,7 @@ S_make_matcher(pTHX_ REGEXP *re)
     PM_SETRE(matcher, ReREFCNT_inc(re));
 
     SAVEFREEOP((OP *) matcher);
-    ENTER; SAVETMPS;
+    ENTER_with_name("matcher"); SAVETMPS;
     SAVEOP();
     return matcher;
 }
@@ -3981,7 +4111,7 @@ S_destroy_matcher(pTHX_ PMOP *matcher)
     PERL_UNUSED_ARG(matcher);
 
     FREETMPS;
-    LEAVE;
+    LEAVE_with_name("matcher");
 }
 
 /* Do a smart match */
@@ -4068,7 +4198,7 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 		RETPUSHYES;
 	    while ( (he = hv_iternext(hv)) ) {
 		DEBUG_M(Perl_deb(aTHX_ "        testing hash key...\n"));
-		ENTER;
+		ENTER_with_name("smartmatch_hash_key_test");
 		SAVETMPS;
 		PUSHMARK(SP);
 		PUSHs(hv_iterkeysv(he));
@@ -4080,7 +4210,7 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 		else
 		    andedresults = SvTRUEx(POPs) && andedresults;
 		FREETMPS;
-		LEAVE;
+		LEAVE_with_name("smartmatch_hash_key_test");
 	    }
 	    if (andedresults)
 		RETPUSHYES;
@@ -4099,7 +4229,7 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 	    for (i = 0; i <= len; ++i) {
 		SV * const * const svp = av_fetch(av, i, FALSE);
 		DEBUG_M(Perl_deb(aTHX_ "        testing array element...\n"));
-		ENTER;
+		ENTER_with_name("smartmatch_array_elem_test");
 		SAVETMPS;
 		PUSHMARK(SP);
 		if (svp)
@@ -4112,7 +4242,7 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 		else
 		    andedresults = SvTRUEx(POPs) && andedresults;
 		FREETMPS;
-		LEAVE;
+		LEAVE_with_name("smartmatch_array_elem_test");
 	    }
 	    if (andedresults)
 		RETPUSHYES;
@@ -4122,7 +4252,7 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 	else {
 	  sm_any_sub:
 	    DEBUG_M(Perl_deb(aTHX_ "    applying rule Any-CodeRef\n"));
-	    ENTER;
+	    ENTER_with_name("smartmatch_coderef");
 	    SAVETMPS;
 	    PUSHMARK(SP);
 	    PUSHs(d);
@@ -4134,7 +4264,7 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 	    else if (SvTEMP(TOPs))
 		SvREFCNT_inc_void(TOPs);
 	    FREETMPS;
-	    LEAVE;
+	    LEAVE_with_name("smartmatch_coderef");
 	    RETURN;
 	}
     }
@@ -4285,7 +4415,7 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 		    (void) sv_2mortal(MUTABLE_SV(seen_this));
 		}
 		if (NULL == seen_other) {
-		    seen_this = newHV();
+		    seen_other = newHV();
 		    (void) sv_2mortal(MUTABLE_SV(seen_other));
 		}
 		for(i = 0; i <= other_len; ++i) {
@@ -4293,7 +4423,8 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 		    SV * const * const other_elem = av_fetch(other_av, i, FALSE);
 
 		    if (!this_elem || !other_elem) {
-			if (this_elem || other_elem)
+			if ((this_elem && SvOK(*this_elem))
+				|| (other_elem && SvOK(*other_elem)))
 			    RETPUSHNO;
 		    }
 		    else if (hv_exists_ent(seen_this,
@@ -4479,7 +4610,7 @@ PP(pp_enterwhen)
     if ((0 == (PL_op->op_flags & OPf_SPECIAL)) && !SvTRUEx(POPs))
 	return cLOGOP->op_other->op_next;
 
-    ENTER;
+    ENTER_with_name("eval");
     SAVETMPS;
 
     PUSHBLOCK(cx, CXt_WHEN, SP);
@@ -4504,7 +4635,7 @@ PP(pp_leavewhen)
 
     PL_curpm = newpm;   /* pop $1 et al */
 
-    LEAVE;
+    LEAVE_with_name("eval");
     return NORMAL;
 }
 
@@ -4821,8 +4952,8 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
     int status = 0;
     SV *upstream;
     STRLEN got_len;
-    const char *got_p = NULL;
-    const char *prune_from = NULL;
+    char *got_p = NULL;
+    char *prune_from = NULL;
     bool read_from_cache = FALSE;
     STRLEN umaxlen;
 
@@ -4836,8 +4967,8 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
        for PL_parser->error_count == 0.)  Solaris doesn't segfault --
        not sure where the trouble is yet.  XXX */
 
-    if (IoFMT_GV(datasv)) {
-	SV *const cache = MUTABLE_SV(IoFMT_GV(datasv));
+    {
+	SV *const cache = datasv;
 	if (SvOK(cache)) {
 	    STRLEN cache_len;
 	    const char *cache_p = SvPV(cache, cache_len);
@@ -4891,7 +5022,7 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 	dSP;
 	int count;
 
-	ENTER;
+	ENTER_with_name("call_filter_sub");
 	SAVE_DEFSV;
 	SAVETMPS;
 	EXTEND(SP, 2);
@@ -4915,7 +5046,7 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 
 	PUTBACK;
 	FREETMPS;
-	LEAVE;
+	LEAVE_with_name("call_filter_sub");
     }
 
     if(SvOK(upstream)) {
@@ -4925,8 +5056,7 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 		prune_from = got_p + umaxlen;
 	    }
 	} else {
-	    const char *const first_nl =
-		(const char *)memchr(got_p, '\n', got_len);
+	    char *const first_nl = (char *)memchr(got_p, '\n', got_len);
 	    if (first_nl && first_nl + 1 < got_p + got_len) {
 		/* There's a second line here... */
 		prune_from = first_nl + 1;
@@ -4936,11 +5066,9 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
     if (prune_from) {
 	/* Oh. Too long. Stuff some in our cache.  */
 	STRLEN cached_len = got_p + got_len - prune_from;
-	SV *cache = MUTABLE_SV(IoFMT_GV(datasv));
+	SV *const cache = datasv;
 
-	if (!cache) {
-	    IoFMT_GV(datasv) = MUTABLE_GV((cache = newSV(got_len - umaxlen)));
-	} else if (SvOK(cache)) {
+	if (SvOK(cache)) {
 	    /* Cache should be empty.  */
 	    assert(!SvCUR(cache));
 	}
@@ -4954,6 +5082,7 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 	    SvUTF8_on(cache);
 	}
 	SvCUR_set(upstream, got_len - cached_len);
+	*prune_from = 0;
 	/* Can't yet be EOF  */
 	if (status == 0)
 	    status = 1;
@@ -4969,7 +5098,6 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 
     if (status <= 0) {
 	IoLINES(datasv) = 0;
-	SvREFCNT_dec(IoFMT_GV(datasv));
 	if (filter_state) {
 	    SvREFCNT_dec(filter_state);
 	    IoTOP_GV(datasv) = NULL;