This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Convert Devel::Peek's test to Test::More.
[perl5.git] / pp_ctl.c
index ce60ea0..7d041bd 100644 (file)
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -96,6 +96,7 @@ PP(pp_regcomp)
 
 #define tryAMAGICregexp(rx)                    \
     STMT_START {                               \
+       SvGETMAGIC(rx);                         \
        if (SvROK(rx) && SvAMAGIC(rx)) {        \
            SV *sv = AMG_CALLun(rx, regexp);    \
            if (sv) {                           \
@@ -149,6 +150,27 @@ PP(pp_regcomp)
        re = (REGEXP*) tmpstr;
 
     if (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);
@@ -243,6 +265,9 @@ 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);
@@ -257,9 +282,11 @@ 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);
 
@@ -298,7 +325,10 @@ PP(pp_substcont)
            SvPV_set(dstr, NULL);
 
            TAINT_IF(cx->sb_rxtainted & 1);
-           mPUSHi(saviters - 1);
+           if (pm->op_pmflags & PMf_NONDESTRUCT)
+               PUSHs(targ);
+           else
+               mPUSHi(saviters - 1);
 
            (void)SvPOK_only_UTF8(targ);
            TAINT_IF(cx->sb_rxtainted);
@@ -996,14 +1026,14 @@ 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];
@@ -1084,13 +1114,13 @@ 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 */
@@ -1113,7 +1143,7 @@ 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 */
@@ -1313,13 +1343,16 @@ 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;
@@ -1386,7 +1419,7 @@ 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;
        }
     }
@@ -1404,7 +1437,7 @@ 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;
        }
     }
@@ -1433,7 +1466,7 @@ 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;
        }
     }
@@ -1451,7 +1484,7 @@ 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));
@@ -1460,7 +1493,7 @@ 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;
            }
        }
@@ -1479,7 +1512,7 @@ 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;
        }
     }
@@ -1495,8 +1528,7 @@ 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:
@@ -1543,49 +1575,18 @@ Perl_qerror(pTHX_ SV *err)
        ++PL_parser->error_count;
 }
 
-OP *
-Perl_die_where(pTHX_ SV *msv)
+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 (msv) {
-           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)+SvCUR(msv)-1) {
-                   STRLEN len;
-                   STRLEN msglen;
-                   const char* message = SvPV_const(msv, msglen);
-                   e = SvPV_const(err, len);
-                   e += len - msglen;
-                   if (*e != *message || strNE(e,message))
-                       e = NULL;
-               }
-               if (!e) {
-                   STRLEN start;
-                   SvGROW(err, SvCUR(err)+sizeof(prefix)+SvCUR(msv));
-                   sv_catpvn(err, prefix, sizeof(prefix)-1);
-                   sv_catsv(err, msv);
-                   start = SvCUR(err)-SvCUR(msv)-sizeof(prefix)+1;
-                   Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "%s",
-                                  SvPVX_const(err)+start);
-               }
-           }
-           else {
-               STRLEN msglen;
-               const char* message = SvPV_const(msv, msglen);
-               sv_setpvn(ERRSV, message, msglen);
-               SvFLAGS(ERRSV) |= SvFLAGS(msv) & SVf_UTF8;
-           }
-       }
-
        while ((cxix = dopoptoeval(cxstack_ix)) < 0
               && PL_curstackinfo->si_prev)
        {
@@ -1595,6 +1596,7 @@ Perl_die_where(pTHX_ SV *msv)
 
        if (cxix >= 0) {
            I32 optype;
+           SV *namesv;
            register PERL_CONTEXT *cx;
            SV **newsp;
 
@@ -1604,12 +1606,13 @@ Perl_die_where(pTHX_ SV *msv)
            POPBLOCK(cx,PL_curpm);
            if (CxTYPE(cx) != CXt_EVAL) {
                STRLEN msglen;
-               const char* message = SvPVx_const( msv ? msv : ERRSV, 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;
@@ -1624,22 +1627,35 @@ Perl_die_where(pTHX_ SV *msv)
            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);
-               DIE(aTHX_ "%sCompilation failed in require",
-                   *msg ? msg : "Unknown error\n");
+               /* 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 */
+               Perl_croak(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 */
        }
     }
 
-    write_to_stderr( msv ? msv : ERRSV );
+    write_to_stderr(exceptsv);
     my_failure_exit();
     /* NOTREACHED */
-    return 0;
 }
 
 PP(pp_xor)
@@ -1840,6 +1856,8 @@ 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))
     {
@@ -1900,7 +1918,7 @@ PP(pp_enteriter)
     PAD *iterdata;
 #endif
 
-    ENTER;
+    ENTER_with_name("loop1");
     SAVETMPS;
 
     if (PL_op->op_targ) {
@@ -1929,7 +1947,7 @@ 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
@@ -2026,9 +2044,9 @@ 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);
@@ -2071,8 +2089,8 @@ 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;
 }
@@ -2087,8 +2105,9 @@ 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);
 
@@ -2129,6 +2148,7 @@ 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;
@@ -2137,9 +2157,10 @@ 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:
@@ -2210,7 +2231,7 @@ PP(pp_last)
     I32 pop2 = 0;
     I32 gimme;
     I32 optype;
-    OP *nextop;
+    OP *nextop = NULL;
     SV **newsp;
     PMOP *newpm;
     SV **mark;
@@ -2392,9 +2413,11 @@ 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)
@@ -2620,6 +2643,8 @@ PP(pp_goto)
     else
        label = cPVOP->op_pv;
 
+    PERL_ASYNC_CHECK();
+
     if (label && *label) {
        OP *gotoprobe = NULL;
        bool leaving_eval = FALSE;
@@ -2697,6 +2722,12 @@ 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) {
@@ -2798,6 +2829,20 @@ 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)
 {
@@ -2822,17 +2867,8 @@ 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;
@@ -2849,13 +2885,20 @@ 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;
@@ -2871,7 +2914,7 @@ 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 */
@@ -2932,7 +2975,7 @@ 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
@@ -2986,6 +3029,35 @@ 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.
@@ -3000,8 +3072,10 @@ 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);
 
@@ -3053,36 +3127,61 @@ 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"));
        }
@@ -3091,7 +3190,6 @@ 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;
@@ -3103,14 +3201,8 @@ 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);
@@ -3249,36 +3341,37 @@ 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)));
                }
            }
        }
 
-        /* We do this only with use, not require. */
+       /* We do this only with "use", not "require" or "no". */
        if (PL_compcv &&
+               !(cUNOP->op_first->op_private & OPpCONST_NOVER) &&
          /* If we request a version >= 5.9.5, load feature.pm with the
           * feature bundle that corresponds to the required version. */
                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 &&
@@ -3361,7 +3454,7 @@ PP(pp_require)
                    tryname = SvPVX_const(namesv);
                    tryrsfp = NULL;
 
-                   ENTER;
+                   ENTER_with_name("call_INC");
                    SAVETMPS;
                    EXTEND(SP, 2);
 
@@ -3375,11 +3468,6 @@ PP(pp_require)
                        count = call_sv(loader, G_ARRAY);
                    SPAGAIN;
 
-                   /* Adjust file name if the hook has set an %INC entry */
-                   svp = hv_fetch(GvHVn(PL_incgv), name, len, 0);
-                   if (svp)
-                       tryname = SvPV_nolen_const(*svp);
-
                    if (count > 0) {
                        int i = 0;
                        SV *arg;
@@ -3439,7 +3527,13 @@ PP(pp_require)
 
                    PUTBACK;
                    FREETMPS;
-                   LEAVE;
+                   LEAVE_with_name("call_INC");
+
+                   /* Adjust file name if the hook has set an %INC entry.
+                      This needs to happen after the FREETMPS above.  */
+                   svp = hv_fetch(GvHVn(PL_incgv), name, len, 0);
+                   if (svp)
+                       tryname = SvPV_nolen_const(*svp);
 
                    if (tryrsfp) {
                        hook_sv = dirsv;
@@ -3533,39 +3627,39 @@ PP(pp_require)
            }
        }
     }
-    SAVECOPFILE_FREE(&PL_compiling);
-    CopFILE_set(&PL_compiling, tryrsfp ? tryname : name);
+    if (tryrsfp) {
+       SAVECOPFILE_FREE(&PL_compiling);
+       CopFILE_set(&PL_compiling, tryname);
+    }
     SvREFCNT_dec(namesv);
     if (!tryrsfp) {
        if (PL_op->op_type == OP_REQUIRE) {
-           const char *msgstr = name;
            if(errno == EMFILE) {
-               SV * const msg
-                   = sv_2mortal(Perl_newSVpvf(aTHX_ "%s:   %s", msgstr,
-                                              Strerror(errno)));
-               msgstr = SvPV_nolen_const(msg);
+               /* diag_listed_as: Can't locate %s */
+               DIE(aTHX_ "Can't locate %s:   %s", name, Strerror(errno));
            } else {
                if (namesv) {                   /* did we lookup @INC? */
                    AV * const ar = GvAVn(PL_incgv);
                    I32 i;
-                   SV * const msg = sv_2mortal(Perl_newSVpvf(aTHX_ 
-                       "%s in @INC%s%s (@INC contains:",
-                       msgstr,
-                       (instr(msgstr, ".h ")
-                        ? " (change .h to .ph maybe?)" : ""),
-                       (instr(msgstr, ".ph ")
-                        ? " (did you run h2ph?)" : "")
-                                                             ));
-                   
+                   SV *const inc = newSVpvs_flags("", SVs_TEMP);
                    for (i = 0; i <= AvFILL(ar); i++) {
-                       sv_catpvs(msg, " ");
-                       sv_catsv(msg, *av_fetch(ar, i, TRUE));
+                       sv_catpvs(inc, " ");
+                       sv_catsv(inc, *av_fetch(ar, i, TRUE));
                    }
-                   sv_catpvs(msg, ")");
-                   msgstr = SvPV_nolen_const(msg);
-               }    
+
+                   /* diag_listed_as: Can't locate %s */
+                   DIE(aTHX_
+                       "Can't locate %s in @INC%s%s (@INC contains:%" SVf ")",
+                       name,
+                       (memEQ(name + len - 2, ".h", 3)
+                        ? " (change .h to .ph maybe?) (did you run h2ph?)" : ""),
+                       (memEQ(name + len - 3, ".ph", 4)
+                        ? " (did you run h2ph?)" : ""),
+                       inc
+                       );
+               }
            }
-           DIE(aTHX_ "Can't locate %s", msgstr);
+           DIE(aTHX_ "Can't locate %s", name);
        }
 
        RETPUSHUNDEF;
@@ -3586,7 +3680,7 @@ PP(pp_require)
                           unixname, unixlen, SvREFCNT_inc_simple(hook_sv), 0 );
     }
 
-    ENTER;
+    ENTER_with_name("eval");
     SAVETMPS;
     lex_start(NULL, tryrsfp, TRUE);
 
@@ -3673,7 +3767,7 @@ PP(pp_entereval)
     TAINT_IF(SvTAINTED(sv));
     TAINT_PROPER("eval");
 
-    ENTER;
+    ENTER_with_name("eval");
     lex_start(sv, NULL, FALSE);
     SAVETMPS;
 
@@ -3710,7 +3804,18 @@ 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++;
@@ -3768,9 +3873,11 @@ 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;
@@ -3811,13 +3918,15 @@ 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();
        }
@@ -3840,7 +3949,7 @@ 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);
@@ -3854,7 +3963,7 @@ 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);
@@ -3922,7 +4031,7 @@ PP(pp_leavetry)
     }
     PL_curpm = newpm;  /* Don't pop $1 et al till now */
 
-    LEAVE;
+    LEAVE_with_name("eval_scope");
     CLEAR_ERRSV();
     RETURN;
 }
@@ -3933,7 +4042,7 @@ 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);
@@ -3956,14 +4065,38 @@ PP(pp_leavegiven)
     POPBLOCK(cx,newpm);
     assert(CxTYPE(cx) == CXt_GIVEN);
 
-    SP = newsp;
-    PUTBACK;
-
-    PL_curpm = newpm;   /* pop $1 et al */
-
-    LEAVE;
+    TAINT_NOT;
+    if (gimme == G_VOID)
+       SP = newsp;
+    else if (gimme == G_SCALAR) {
+       register SV **mark;
+       MARK = newsp + 1;
+       if (MARK <= SP) {
+           if (SvFLAGS(TOPs) & (SVs_PADTMP|SVs_TEMP))
+               *MARK = TOPs;
+           else
+               *MARK = sv_mortalcopy(TOPs);
+       }
+       else {
+           MEXTEND(mark,0);
+           *MARK = &PL_sv_undef;
+       }
+       SP = MARK;
+    }
+    else {
+       /* in case LEAVE wipes old return values */
+       register SV **mark;
+       for (mark = newsp + 1; mark <= SP; mark++) {
+           if (!(SvFLAGS(*mark) & (SVs_PADTMP|SVs_TEMP))) {
+               *mark = sv_mortalcopy(*mark);
+               TAINT_NOT;      /* Each item is independent */
+           }
+       }
+    }
+    PL_curpm = newpm;  /* Don't pop $1 et al till now */
 
-    return NORMAL;
+    LEAVE_with_name("given");
+    RETURN;
 }
 
 /* Helper routines used by pp_smartmatch */
@@ -3978,7 +4111,7 @@ 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;
 }
@@ -4008,7 +4141,7 @@ S_destroy_matcher(pTHX_ PMOP *matcher)
     PERL_UNUSED_ARG(matcher);
 
     FREETMPS;
-    LEAVE;
+    LEAVE_with_name("matcher");
 }
 
 /* Do a smart match */
@@ -4031,6 +4164,19 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
     SV *e = TOPs;      /* e is for 'expression' */
     SV *d = TOPm1s;    /* d is for 'default', as in PL_defgv */
 
+    /* Take care only to invoke mg_get() once for each argument.
+     * Currently we do this by copying the SV if it's magical. */
+    if (d) {
+       if (SvGMAGICAL(d))
+           d = sv_mortalcopy(d);
+    }
+    else
+       d = &PL_sv_undef;
+
+    assert(e);
+    if (SvGMAGICAL(e))
+       e = sv_mortalcopy(e);
+
     /* First of all, handle overload magic of the rightmost argument */
     if (SvAMAGIC(e)) {
        SV * tmpsv;
@@ -4049,18 +4195,6 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 
     SP -= 2;   /* Pop the values */
 
-    /* Take care only to invoke mg_get() once for each argument. 
-     * Currently we do this by copying the SV if it's magical. */
-    if (d) {
-       if (SvGMAGICAL(d))
-           d = sv_mortalcopy(d);
-    }
-    else
-       d = &PL_sv_undef;
-
-    assert(e);
-    if (SvGMAGICAL(e))
-       e = sv_mortalcopy(e);
 
     /* ~~ undef */
     if (!SvOK(e)) {
@@ -4095,7 +4229,7 @@ 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));
@@ -4107,7 +4241,7 @@ 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;
@@ -4126,7 +4260,7 @@ 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)
@@ -4139,7 +4273,7 @@ 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;
@@ -4149,7 +4283,7 @@ 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);
@@ -4161,7 +4295,7 @@ 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;
        }
     }
@@ -4312,7 +4446,7 @@ 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) {
@@ -4320,7 +4454,8 @@ 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,
@@ -4502,11 +4637,12 @@ PP(pp_enterwhen)
        fails, we don't want to push a context and then
        pop it again right away, so we skip straight
        to the op that follows the leavewhen.
+       RETURNOP calls PUTBACK which restores the stack pointer after the POPs.
     */
     if ((0 == (PL_op->op_flags & OPf_SPECIAL)) && !SvTRUEx(POPs))
-       return cLOGOP->op_other->op_next;
+       RETURNOP(cLOGOP->op_other->op_next);
 
-    ENTER;
+    ENTER_with_name("eval");
     SAVETMPS;
 
     PUSHBLOCK(cx, CXt_WHEN, SP);
@@ -4531,7 +4667,7 @@ PP(pp_leavewhen)
 
     PL_curpm = newpm;   /* pop $1 et al */
 
-    LEAVE;
+    LEAVE_with_name("eval");
     return NORMAL;
 }
 
@@ -4563,7 +4699,8 @@ PP(pp_break)
     I32 cxix;
     register PERL_CONTEXT *cx;
     I32 inner;
-    
+    dSP;
+
     cxix = dopoptogiven(cxstack_ix); 
     if (cxix < 0) {
        if (PL_op->op_flags & OPf_SPECIAL)
@@ -4587,7 +4724,8 @@ PP(pp_break)
     if (CxFOREACH(cx))
        return CX_LOOP_NEXTOP_GET(cx);
     else
-       return cx->blk_givwhen.leave_op;
+       /* RETURNOP calls PUTBACK which restores the old old sp */
+       RETURNOP(cx->blk_givwhen.leave_op);
 }
 
 STATIC OP *
@@ -4848,8 +4986,8 @@ 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;
 
@@ -4918,7 +5056,7 @@ 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);
@@ -4942,7 +5080,7 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 
        PUTBACK;
        FREETMPS;
-       LEAVE;
+       LEAVE_with_name("call_filter_sub");
     }
 
     if(SvOK(upstream)) {
@@ -4952,8 +5090,7 @@ 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;
@@ -4979,6 +5116,7 @@ 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;