X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=mg.c;h=6cd1c6fcc3a2250f5163fa55b86f0d22be2760c7;hb=2bbb3949e88673e7f0574ab70254a46d776242e9;hp=58a5cd54601f9b35194a4a4387783c397a0f21ce;hpb=16bd9a85dbc3be76d00459adeafa5bf918a5212d;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/mg.c b/mg.c
index 58a5cd5..6cd1c6f 100644
--- a/mg.c
+++ b/mg.c
@@ -1,6 +1,7 @@
 /*    mg.c
  *
- *    Copyright (c) 1991-2002, Larry Wall
+ *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ *    2000, 2001, 2002, 2003, 2004, 2005 by Larry Wall and others
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
@@ -14,6 +15,24 @@
 
 /*
 =head1 Magical Functions
+
+"Magic" is special data attached to SV structures in order to give them
+"magical" properties.  When any Perl code tries to read from, or assign to,
+an SV marked as magical, it calls the 'get' or 'set' function associated
+with that SV's magic. A get is called prior to reading an SV, in order to
+give it a chance to update its internal value (get on $. writes the line
+number of the last read filehandle into to the SV's IV slot), while
+set is called after an SV has been written to, in order to allow it to make
+use of its changed value (set on $/ copies the SV's new value to the
+PL_rs global variable).
+
+Magic is implemented as a linked list of MAGIC structures attached to the
+SV. Each MAGIC struct holds the type of the magic, a pointer to an array
+of functions that implement the get(), set(), length() etc functions,
+plus space for some flags and pointers. For example, a tied variable has
+a MAGIC structure that contains a pointer to the object associated with the
+tie.
+
 */
 
 #include "EXTERN.h"
@@ -33,6 +52,8 @@
 #  include <sys/pstat.h>
 #endif
 
+Signal_t Perl_csighandler(int sig);
+
 /* if you only have signal() and it resets on each signal, FAKE_PERSISTENT_SIGNAL_HANDLERS fixes */
 #if !defined(HAS_SIGACTION) && defined(VMS)
 #  define  FAKE_PERSISTENT_SIGNAL_HANDLERS
@@ -42,8 +63,16 @@
 #  define  FAKE_DEFAULT_SIGNAL_HANDLERS
 #endif
 
-static void restore_magic(pTHX_ void *p);
-static void unwind_handler_stack(pTHX_ void *p);
+static void restore_magic(pTHX_ const void *p);
+static void unwind_handler_stack(pTHX_ const void *p);
+
+#ifdef __Lynx__
+/* Missing protos on LynxOS */
+void setruid(uid_t id);
+void seteuid(uid_t id);
+void setrgid(uid_t id);
+void setegid(uid_t id);
+#endif
 
 /*
  * Use the "DESTRUCTOR" scope cleanup to reinstate magic.
@@ -92,7 +121,7 @@ Perl_mg_magical(pTHX_ SV *sv)
 {
     MAGIC* mg;
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+	const MGVTBL* const vtbl = mg->mg_virtual;
 	if (vtbl) {
 	    if (vtbl->svt_get && !(mg->mg_flags & MGf_GSKIP))
 		SvGMAGICAL_on(sv);
@@ -115,9 +144,21 @@ Do magic after a value is retrieved from the SV.  See C<sv_magic>.
 int
 Perl_mg_get(pTHX_ SV *sv)
 {
+    const I32 mgs_ix = SSNEW(sizeof(MGS));
+    const bool was_temp = SvTEMP(sv);
     int new = 0;
     MAGIC *newmg, *head, *cur, *mg;
-    I32 mgs_ix = SSNEW(sizeof(MGS));
+    /* guard against sv having being freed midway by holding a private
+       reference. */
+
+    /* sv_2mortal has this side effect of turning on the TEMP flag, which can
+       cause the SV's buffer to get stolen (and maybe other stuff).
+       So restore it.
+    */
+    sv_2mortal(SvREFCNT_inc(sv));
+    if (!was_temp) {
+	SvTEMP_off(sv);
+    }
 
     save_magic(mgs_ix, sv);
 
@@ -127,10 +168,16 @@ Perl_mg_get(pTHX_ SV *sv)
 
     newmg = cur = head = mg = SvMAGIC(sv);
     while (mg) {
-	MGVTBL *vtbl = mg->mg_virtual;
+	const MGVTBL * const vtbl = mg->mg_virtual;
 
 	if (!(mg->mg_flags & MGf_GSKIP) && vtbl && vtbl->svt_get) {
 	    CALL_FPTR(vtbl->svt_get)(aTHX_ sv, mg);
+
+	    /* guard against magic having been deleted - eg FETCH calling
+	     * untie */
+	    if (!SvMAGIC(sv))
+		break;
+
 	    /* Don't restore the flags for this entry if it was deleted. */
 	    if (mg->mg_flags & MGf_GSKIP)
 		(SSPTR(mgs_ix, MGS *))->mgs_flags = 0;
@@ -157,6 +204,12 @@ Perl_mg_get(pTHX_ SV *sv)
     }
 
     restore_magic(aTHX_ INT2PTR(void *, (IV)mgs_ix));
+
+    if (SvREFCNT(sv) == 1) {
+	/* We hold the last reference to this SV, which implies that the
+	   SV was deleted as a side effect of the routines we called.  */
+	SvOK_off(sv);
+    }
     return 0;
 }
 
@@ -171,11 +224,10 @@ Do magic after a value is assigned to the SV.  See C<sv_magic>.
 int
 Perl_mg_set(pTHX_ SV *sv)
 {
-    I32 mgs_ix;
+    const I32 mgs_ix = SSNEW(sizeof(MGS));
     MAGIC* mg;
     MAGIC* nextmg;
 
-    mgs_ix = SSNEW(sizeof(MGS));
     save_magic(mgs_ix, sv);
 
     for (mg = SvMAGIC(sv); mg; mg = nextmg) {
@@ -208,11 +260,9 @@ Perl_mg_length(pTHX_ SV *sv)
     STRLEN len;
 
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL * const vtbl = mg->mg_virtual;
 	if (vtbl && vtbl->svt_len) {
-            I32 mgs_ix;
-
-	    mgs_ix = SSNEW(sizeof(MGS));
+            const I32 mgs_ix = SSNEW(sizeof(MGS));
 	    save_magic(mgs_ix, sv);
 	    /* omit MGf_GSKIP -- not changed here */
 	    len = CALL_FPTR(vtbl->svt_len)(aTHX_ sv, mg);
@@ -221,8 +271,7 @@ Perl_mg_length(pTHX_ SV *sv)
 	}
     }
 
-    if (DO_UTF8(sv))
-    {
+    if (DO_UTF8(sv)) {
         U8 *s = (U8*)SvPV(sv, len);
         len = Perl_utf8_length(aTHX_ s, s + len);
     }
@@ -235,14 +284,12 @@ I32
 Perl_mg_size(pTHX_ SV *sv)
 {
     MAGIC* mg;
-    I32 len;
 
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* const vtbl = mg->mg_virtual;
 	if (vtbl && vtbl->svt_len) {
-            I32 mgs_ix;
-
-	    mgs_ix = SSNEW(sizeof(MGS));
+            const I32 mgs_ix = SSNEW(sizeof(MGS));
+            I32 len;
 	    save_magic(mgs_ix, sv);
 	    /* omit MGf_GSKIP -- not changed here */
 	    len = CALL_FPTR(vtbl->svt_len)(aTHX_ sv, mg);
@@ -253,8 +300,7 @@ Perl_mg_size(pTHX_ SV *sv)
 
     switch(SvTYPE(sv)) {
 	case SVt_PVAV:
-	    len = AvFILLp((AV *) sv); /* Fallback to non-tied array */
-	    return len;
+	    return AvFILLp((AV *) sv); /* Fallback to non-tied array */
 	case SVt_PVHV:
 	    /* FIXME */
 	default:
@@ -275,14 +321,13 @@ Clear something magical that the SV represents.  See C<sv_magic>.
 int
 Perl_mg_clear(pTHX_ SV *sv)
 {
-    I32 mgs_ix;
+    const I32 mgs_ix = SSNEW(sizeof(MGS));
     MAGIC* mg;
 
-    mgs_ix = SSNEW(sizeof(MGS));
     save_magic(mgs_ix, sv);
 
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* const vtbl = mg->mg_virtual;
 	/* omit GSKIP -- never set here */
 
 	if (vtbl && vtbl->svt_clear)
@@ -302,14 +347,14 @@ Finds the magic pointer for type matching the SV.  See C<sv_magic>.
 */
 
 MAGIC*
-Perl_mg_find(pTHX_ SV *sv, int type)
+Perl_mg_find(pTHX_ const SV *sv, int type)
 {
-    MAGIC* mg;
-    if (!sv)
-        return 0;
-    for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	if (mg->mg_type == type)
-	    return mg;
+    if (sv) {
+        MAGIC *mg;
+        for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
+            if (mg->mg_type == type)
+                return mg;
+        }
     }
     return 0;
 }
@@ -328,7 +373,7 @@ Perl_mg_copy(pTHX_ SV *sv, SV *nsv, const char *key, I32 klen)
     int count = 0;
     MAGIC* mg;
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* const vtbl = mg->mg_virtual;
 	if ((mg->mg_flags & MGf_COPY) && vtbl->svt_copy){
 	    count += CALL_FPTR(vtbl->svt_copy)(aTHX_ sv, mg, nsv, key, klen);
 	}
@@ -358,12 +403,12 @@ Perl_mg_free(pTHX_ SV *sv)
     MAGIC* mg;
     MAGIC* moremagic;
     for (mg = SvMAGIC(sv); mg; mg = moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* const vtbl = mg->mg_virtual;
 	moremagic = mg->mg_moremagic;
 	if (vtbl && vtbl->svt_free)
 	    CALL_FPTR(vtbl->svt_free)(aTHX_ sv, mg);
 	if (mg->mg_ptr && mg->mg_type != PERL_MAGIC_regex_global) {
-	    if (mg->mg_len > 0)
+	    if (mg->mg_len > 0 || mg->mg_type == PERL_MAGIC_utf8)
 		Safefree(mg->mg_ptr);
 	    else if (mg->mg_len == HEf_SVKEY)
 		SvREFCNT_dec((SV*)mg->mg_ptr);
@@ -376,15 +421,12 @@ Perl_mg_free(pTHX_ SV *sv)
     return 0;
 }
 
-
-#if !defined(NSIG) || defined(M_UNIX) || defined(M_XENIX)
 #include <signal.h>
-#endif
 
 U32
 Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
 {
-    register REGEXP *rx;
+    register const REGEXP *rx;
 
     if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
 	if (mg->mg_obj)		/* @+ */
@@ -399,20 +441,19 @@ Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_regdatum_get(pTHX_ SV *sv, MAGIC *mg)
 {
-    register I32 paren;
-    register I32 s;
-    register I32 i;
     register REGEXP *rx;
-    I32 t;
 
     if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
-	paren = mg->mg_len;
+        register const I32 paren = mg->mg_len;
+        register I32 s;
+        register I32 t;
 	if (paren < 0)
 	    return 0;
 	if (paren <= (I32)rx->nparens &&
 	    (s = rx->startp[paren]) != -1 &&
 	    (t = rx->endp[paren]) != -1)
 	    {
+                register I32 i;
 		if (mg->mg_obj)		/* @+ */
 		    i = t;
 		else			/* @- */
@@ -473,12 +514,12 @@ Perl_magic_len(pTHX_ SV *sv, MAGIC *mg)
 	    }
 	    else {
 		if (ckWARN(WARN_UNINITIALIZED))
-		    report_uninit();
+		    report_uninit(sv);
 	    }
 	}
 	else {
 	    if (ckWARN(WARN_UNINITIALIZED))
-		report_uninit();
+		report_uninit(sv);
 	}
 	return 0;
     case '+':
@@ -534,7 +575,7 @@ int
 Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 {
     register I32 paren;
-    register char *s;
+    register char *s = NULL;
     register I32 i;
     register REGEXP *rx;
 
@@ -548,9 +589,6 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 
     case '\004':		/* ^D */
 	sv_setiv(sv, (IV)(PL_debug & DEBUG_MASK));
-#if defined(YYDEBUG) && defined(DEBUGGING)
-	PL_yydebug = DEBUG_p_TEST;
-#endif
 	break;
     case '\005':  /* ^E */
 	 if (*(mg->mg_ptr+1) == '\0') {
@@ -602,8 +640,12 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 		  SetLastError(dwErr);
 	     }
 #else
-	     sv_setnv(sv, (NV)errno);
-	     sv_setpv(sv, errno ? Strerror(errno) : "");
+	     {
+		 int saveerrno = errno;
+		 sv_setnv(sv, (NV)errno);
+		 sv_setpv(sv, errno ? Strerror(errno) : "");
+		 errno = saveerrno;
+	     }
 #endif
 #endif
 #endif
@@ -626,8 +668,10 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	    sv_setsv(sv, &PL_sv_undef);
 	break;
     case '\017':		/* ^O & ^OPEN */
-	if (*(mg->mg_ptr+1) == '\0')
+	if (*(mg->mg_ptr+1) == '\0') {
 	    sv_setpv(sv, PL_osname);
+	    SvTAINTED_off(sv);
+	}
 	else if (strEQ(mg->mg_ptr, "\017PEN")) {
 	    if (!PL_compiling.cop_io)
 		sv_setsv(sv, &PL_sv_undef);
@@ -642,7 +686,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
     case '\023':		/* ^S */
         if (*(mg->mg_ptr+1) == '\0') {
 	    if (PL_lex_state != LEX_NOTPARSING)
-		(void)SvOK_off(sv);
+		SvOK_off(sv);
 	    else if (PL_in_eval)
  		sv_setiv(sv, PL_in_eval & ~(EVAL_INREQUIRE));
 	    else
@@ -662,9 +706,11 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 		    ? (PL_taint_warn || PL_unsafe ? -1 : 1)
 		    : 0);
         break;
-    case '\025':		/* $^UNICODE */
+    case '\025':		/* $^UNICODE, $^UTF8LOCALE */
         if (strEQ(mg->mg_ptr, "\025NICODE"))
 	    sv_setuv(sv, (UV) PL_unicode);
+        else if (strEQ(mg->mg_ptr, "\025TF8LOCALE"))
+	    sv_setuv(sv, (UV) PL_utf8locale);
         break;
     case '\027':		/* ^W  & $^WARNING_BITS */
 	if (*(mg->mg_ptr+1) == '\0')
@@ -676,7 +722,16 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	        sv_setpvn(sv, WARN_NONEstring, WARNsize) ;
             }
             else if (PL_compiling.cop_warnings == pWARN_ALL) {
-	        sv_setpvn(sv, WARN_ALLstring, WARNsize) ;
+		/* Get the bit mask for $warnings::Bits{all}, because
+		 * it could have been extended by warnings::register */
+		SV **bits_all;
+		HV *bits=get_hv("warnings::Bits", FALSE);
+		if (bits && (bits_all=hv_fetch(bits, "all", 3, FALSE))) {
+		    sv_setsv(sv, *bits_all);
+		}
+	        else {
+		    sv_setpvn(sv, WARN_ALLstring, WARNsize) ;
+		}
 	    }
             else {
 	        sv_setsv(sv, PL_compiling.cop_warnings);
@@ -783,7 +838,8 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	}
 	break;
     case '^':
-	s = IoTOP_NAME(GvIOp(PL_defoutgv));
+	if (GvIOp(PL_defoutgv))
+	    s = IoTOP_NAME(GvIOp(PL_defoutgv));
 	if (s)
 	    sv_setpv(sv,s);
 	else {
@@ -792,20 +848,24 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	}
 	break;
     case '~':
-	s = IoFMT_NAME(GvIOp(PL_defoutgv));
+	if (GvIOp(PL_defoutgv))
+	    s = IoFMT_NAME(GvIOp(PL_defoutgv));
 	if (!s)
 	    s = GvENAME(PL_defoutgv);
 	sv_setpv(sv,s);
 	break;
 #ifndef lint
     case '=':
-	sv_setiv(sv, (IV)IoPAGE_LEN(GvIOp(PL_defoutgv)));
+	if (GvIOp(PL_defoutgv))
+	    sv_setiv(sv, (IV)IoPAGE_LEN(GvIOp(PL_defoutgv)));
 	break;
     case '-':
-	sv_setiv(sv, (IV)IoLINES_LEFT(GvIOp(PL_defoutgv)));
+	if (GvIOp(PL_defoutgv))
+	    sv_setiv(sv, (IV)IoLINES_LEFT(GvIOp(PL_defoutgv)));
 	break;
     case '%':
-	sv_setiv(sv, (IV)IoPAGE(GvIOp(PL_defoutgv)));
+	if (GvIOp(PL_defoutgv))
+	    sv_setiv(sv, (IV)IoPAGE(GvIOp(PL_defoutgv)));
 	break;
 #endif
     case ':':
@@ -816,7 +876,8 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	WITH_THR(sv_setiv(sv, (IV)PL_curcop->cop_arybase));
 	break;
     case '|':
-	sv_setiv(sv, (IV)(IoFLAGS(GvIOp(PL_defoutgv)) & IOf_FLUSH) != 0 );
+	if (GvIOp(PL_defoutgv))
+	    sv_setiv(sv, (IV)(IoFLAGS(GvIOp(PL_defoutgv)) & IOf_FLUSH) != 0 );
 	break;
     case ',':
 	break;
@@ -874,8 +935,6 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 #endif
 	(void)SvIOK_on(sv);	/* what a wonderful hack! */
 	break;
-    case '*':
-	break;
 #ifndef MACOS_TRADITIONAL
     case '0':
 	break;
@@ -1002,6 +1061,7 @@ Perl_magic_set_all_env(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
 {
+#ifndef PERL_MICRO
 #if defined(VMS) || defined(EPOC)
     Perl_die(aTHX_ "Can't make list assignment to %%ENV on this system");
 #else
@@ -1015,6 +1075,7 @@ Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
 #      endif
     {
 #      ifndef PERL_USE_SAFE_PUTENV
+    if (!PL_use_safe_putenv) {
     I32 i;
 
     if (environ == PL_origenviron)
@@ -1022,13 +1083,15 @@ Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
     else
 	for (i = 0; environ[i]; i++)
 	    safesysfree(environ[i]);
+    }
 #      endif /* PERL_USE_SAFE_PUTENV */
 
     environ[0] = Nullch;
     }
 #    endif /* USE_ENVIRON_ARRAY */
 #   endif /* PERL_IMPLICIT_SYS || WIN32 */
-#endif /* VMS || EPC */
+#endif /* VMS || EPOC */
+#endif /* !PERL_MICRO */
     return 0;
 }
 
@@ -1043,6 +1106,14 @@ static int sig_defaulting[SIG_SIZE];
 #endif
 
 #ifndef PERL_MICRO
+#ifdef HAS_SIGPROCMASK
+static void
+restore_sigmask(pTHX_ SV *save_sv)
+{
+    sigset_t *ossetp = (sigset_t *) SvPV_nolen( save_sv );
+    (void)sigprocmask(SIG_SETMASK, ossetp, (sigset_t *)0);
+}
+#endif
 int
 Perl_magic_getsig(pTHX_ SV *sv, MAGIC *mg)
 {
@@ -1050,7 +1121,7 @@ Perl_magic_getsig(pTHX_ SV *sv, MAGIC *mg)
     STRLEN n_a;
     /* Are we fetching a signal entry? */
     i = whichsig(MgPV(mg,n_a));
-    if (i) {
+    if (i > 0) {
     	if(PL_psig_ptr[i])
     	    sv_setsv(sv,PL_psig_ptr[i]);
     	else {
@@ -1076,19 +1147,66 @@ Perl_magic_getsig(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
 {
-    I32 i;
+    /* XXX Some of this code was copied from Perl_magic_setsig. A little
+     * refactoring might be in order.
+     */
     STRLEN n_a;
-    /* Are we clearing a signal entry? */
-    i = whichsig(MgPV(mg,n_a));
-    if (i) {
-    	if(PL_psig_ptr[i]) {
-    	    SvREFCNT_dec(PL_psig_ptr[i]);
-    	    PL_psig_ptr[i]=0;
-    	}
-    	if(PL_psig_name[i]) {
-    	    SvREFCNT_dec(PL_psig_name[i]);
-    	    PL_psig_name[i]=0;
-    	}
+    SV* to_dec;
+    register const char *s = MgPV(mg,n_a);
+    if (*s == '_') {
+	SV** svp;
+	if (strEQ(s,"__DIE__"))
+	    svp = &PL_diehook;
+	else if (strEQ(s,"__WARN__"))
+	    svp = &PL_warnhook;
+	else
+	    Perl_croak(aTHX_ "No such hook: %s", s);
+	if (*svp) {
+	    to_dec = *svp;
+	    *svp = 0;
+    	    SvREFCNT_dec(to_dec);
+	}
+    }
+    else {
+	I32 i;
+	/* Are we clearing a signal entry? */
+	i = whichsig(s);
+	if (i > 0) {
+#ifdef HAS_SIGPROCMASK
+	    sigset_t set, save;
+	    SV* save_sv;
+	    /* Avoid having the signal arrive at a bad time, if possible. */
+	    sigemptyset(&set);
+	    sigaddset(&set,i);
+	    sigprocmask(SIG_BLOCK, &set, &save);
+	    ENTER;
+	    save_sv = newSVpv((char *)(&save), sizeof(sigset_t));
+	    SAVEFREESV(save_sv);
+	    SAVEDESTRUCTOR_X(restore_sigmask, save_sv);
+#endif
+	    PERL_ASYNC_CHECK();
+#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS) || defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
+	    if (!sig_handlers_initted) Perl_csighandler_init();
+#endif
+#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
+	    sig_defaulting[i] = 1;
+	    (void)rsignal(i, PL_csighandlerp);
+#else
+	    (void)rsignal(i, SIG_DFL);
+#endif
+    	    if(PL_psig_name[i]) {
+    		SvREFCNT_dec(PL_psig_name[i]);
+    		PL_psig_name[i]=0;
+    	    }
+    	    if(PL_psig_ptr[i]) {
+		to_dec=PL_psig_ptr[i];
+    		PL_psig_ptr[i]=0;
+		LEAVE;
+    		SvREFCNT_dec(to_dec);
+    	    }
+	    else
+		LEAVE;
+	}
     }
     return 0;
 }
@@ -1111,7 +1229,7 @@ Perl_csighandler(int sig)
     dTHX;
 #endif
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
-    (void) rsignal(sig, &Perl_csighandler);
+    (void) rsignal(sig, PL_csighandlerp);
     if (sig_ignoring[sig]) return;
 #endif
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
@@ -1141,7 +1259,7 @@ Perl_csighandler_init(void)
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
         dTHX;
         sig_defaulting[sig] = 1;
-        (void) rsignal(sig, &Perl_csighandler);
+        (void) rsignal(sig, PL_csighandlerp);
 #endif
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
         sig_ignoring[sig] = 0;
@@ -1170,12 +1288,20 @@ Perl_despatch_signals(pTHX)
 int
 Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 {
-    register char *s;
     I32 i;
     SV** svp = 0;
+    /* Need to be careful with SvREFCNT_dec(), because that can have side
+     * effects (due to closures). We must make sure that the new disposition
+     * is in place before it is called.
+     */
+    SV* to_dec = 0;
     STRLEN len;
+#ifdef HAS_SIGPROCMASK
+    sigset_t set, save;
+    SV* save_sv;
+#endif
 
-    s = MgPV(mg,len);
+    register const char *s = MgPV(mg,len);
     if (*s == '_') {
 	if (strEQ(s,"__DIE__"))
 	    svp = &PL_diehook;
@@ -1185,17 +1311,28 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 	    Perl_croak(aTHX_ "No such hook: %s", s);
 	i = 0;
 	if (*svp) {
-	    SvREFCNT_dec(*svp);
+	    to_dec = *svp;
 	    *svp = 0;
 	}
     }
     else {
 	i = whichsig(s);	/* ...no, a brick */
-	if (!i) {
+	if (i < 0) {
 	    if (ckWARN(WARN_SIGNAL))
 		Perl_warner(aTHX_ packWARN(WARN_SIGNAL), "No such signal: SIG%s", s);
 	    return 0;
 	}
+#ifdef HAS_SIGPROCMASK
+	/* Avoid having the signal arrive at a bad time, if possible. */
+	sigemptyset(&set);
+	sigaddset(&set,i);
+	sigprocmask(SIG_BLOCK, &set, &save);
+	ENTER;
+	save_sv = newSVpv((char *)(&save), sizeof(sigset_t));
+	SAVEFREESV(save_sv);
+	SAVEDESTRUCTOR_X(restore_sigmask, save_sv);
+#endif
+	PERL_ASYNC_CHECK();
 #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS) || defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
 	if (!sig_handlers_initted) Perl_csighandler_init();
 #endif
@@ -1203,20 +1340,26 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 	sig_ignoring[i] = 0;
 #endif
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
-	  sig_defaulting[i] = 0;
+	sig_defaulting[i] = 0;
 #endif
 	SvREFCNT_dec(PL_psig_name[i]);
-	SvREFCNT_dec(PL_psig_ptr[i]);
+	to_dec = PL_psig_ptr[i];
 	PL_psig_ptr[i] = SvREFCNT_inc(sv);
 	SvTEMP_off(sv); /* Make sure it doesn't go away on us */
 	PL_psig_name[i] = newSVpvn(s, len);
 	SvREADONLY_on(PL_psig_name[i]);
     }
     if (SvTYPE(sv) == SVt_PVGV || SvROK(sv)) {
-	if (i)
-	    (void)rsignal(i, &Perl_csighandler);
+	if (i) {
+	    (void)rsignal(i, PL_csighandlerp);
+#ifdef HAS_SIGPROCMASK
+	    LEAVE;
+#endif
+	}
 	else
 	    *svp = SvREFCNT_inc(sv);
+	if(to_dec)
+	    SvREFCNT_dec(to_dec);
 	return 0;
     }
     s = SvPV_force(sv,len);
@@ -1224,25 +1367,22 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 	if (i) {
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
 	    sig_ignoring[i] = 1;
-	    (void)rsignal(i, &Perl_csighandler);
+	    (void)rsignal(i, PL_csighandlerp);
 #else
 	    (void)rsignal(i, SIG_IGN);
 #endif
-	} else
-	    *svp = 0;
+	}
     }
     else if (strEQ(s,"DEFAULT") || !*s) {
 	if (i)
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
 	  {
 	    sig_defaulting[i] = 1;
-	    (void)rsignal(i, &Perl_csighandler);
+	    (void)rsignal(i, PL_csighandlerp);
 	  }
 #else
 	    (void)rsignal(i, SIG_DFL);
 #endif
-	else
-	    *svp = 0;
     }
     else {
 	/*
@@ -1253,10 +1393,16 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 	if (!strchr(s,':') && !strchr(s,'\''))
 	    sv_insert(sv, 0, 0, "main::", 6);
 	if (i)
-	    (void)rsignal(i, &Perl_csighandler);
+	    (void)rsignal(i, PL_csighandlerp);
 	else
 	    *svp = SvREFCNT_inc(sv);
     }
+#ifdef HAS_SIGPROCMASK
+    if(i)
+	LEAVE;
+#endif
+    if(to_dec)
+	SvREFCNT_dec(to_dec);
     return 0;
 }
 #endif /* !PERL_MICRO */
@@ -1356,9 +1502,9 @@ S_magic_methpack(pTHX_ SV *sv, MAGIC *mg, char *meth)
 int
 Perl_magic_getpack(pTHX_ SV *sv, MAGIC *mg)
 {
-    magic_methpack(sv,mg,"FETCH");
     if (mg->mg_ptr)
 	mg->mg_flags |= MGf_GSKIP;
+    magic_methpack(sv,mg,"FETCH");
     return 0;
 }
 
@@ -1413,6 +1559,7 @@ Perl_magic_wipepack(pTHX_ SV *sv, MAGIC *mg)
     call_method("CLEAR", G_SCALAR|G_DISCARD);
     POPSTACK;
     LEAVE;
+
     return 0;
 }
 
@@ -1420,7 +1567,7 @@ int
 Perl_magic_nextpack(pTHX_ SV *sv, MAGIC *mg, SV *key)
 {
     dSP;
-    const char *meth = SvOK(key) ? "NEXTKEY" : "FIRSTKEY";
+    const char * const meth = SvOK(key) ? "NEXTKEY" : "FIRSTKEY";
 
     ENTER;
     SAVETMPS;
@@ -1447,6 +1594,41 @@ Perl_magic_existspack(pTHX_ SV *sv, MAGIC *mg)
     return magic_methpack(sv,mg,"EXISTS");
 }
 
+SV *
+Perl_magic_scalarpack(pTHX_ HV *hv, MAGIC *mg)
+{
+    dSP;
+    SV *retval = &PL_sv_undef;
+    SV *tied = SvTIED_obj((SV*)hv, mg);
+    HV *pkg = SvSTASH((SV*)SvRV(tied));
+   
+    if (!gv_fetchmethod_autoload(pkg, "SCALAR", FALSE)) {
+        SV *key;
+        if (HvEITER(hv))
+            /* we are in an iteration so the hash cannot be empty */
+            return &PL_sv_yes;
+        /* no xhv_eiter so now use FIRSTKEY */
+        key = sv_newmortal();
+        magic_nextpack((SV*)hv, mg, key);
+        HvEITER(hv) = NULL;     /* need to reset iterator */
+        return SvOK(key) ? &PL_sv_yes : &PL_sv_no;
+    }
+   
+    /* there is a SCALAR method that we can call */
+    ENTER;
+    PUSHSTACKi(PERLSI_MAGIC);
+    PUSHMARK(SP);
+    EXTEND(SP, 1);
+    PUSHs(tied);
+    PUTBACK;
+
+    if (call_method("SCALAR", G_SCALAR))
+        retval = *PL_stack_sp--; 
+    POPSTACK;
+    LEAVE;
+    return retval;
+}
+
 int
 Perl_magic_setdbline(pTHX_ SV *sv, MAGIC *mg)
 {
@@ -1499,7 +1681,7 @@ Perl_magic_getpos(pTHX_ SV *sv, MAGIC *mg)
 	    return 0;
 	}
     }
-    (void)SvOK_off(sv);
+    SvOK_off(sv);
     return 0;
 }
 
@@ -1571,16 +1753,11 @@ Perl_magic_getglob(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setglob(pTHX_ SV *sv, MAGIC *mg)
 {
-    register char *s;
     GV* gv;
-    STRLEN n_a;
-
+ 
     if (!SvOK(sv))
 	return 0;
-    s = SvPV(sv, n_a);
-    if (*s == '*' && s[1])
-	s++;
-    gv = gv_fetchpv(s,TRUE, SVt_PVGV);
+    gv = gv_fetchsv(sv,TRUE, SVt_PVGV);
     if (sv == (SV*)gv)
 	return 0;
     if (GvGP(sv))
@@ -1593,8 +1770,8 @@ int
 Perl_magic_getsubstr(pTHX_ SV *sv, MAGIC *mg)
 {
     STRLEN len;
-    SV *lsv = LvTARG(sv);
-    char *tmps = SvPV(lsv,len);
+    SV * const lsv = LvTARG(sv);
+    const char * const tmps = SvPV(lsv,len);
     I32 offs = LvTARGOFF(sv);
     I32 rem = LvTARGLEN(sv);
 
@@ -1623,16 +1800,21 @@ Perl_magic_setsubstr(pTHX_ SV *sv, MAGIC *mg)
 	sv_utf8_upgrade(lsv);
  	sv_pos_u2b(lsv, &lvoff, &lvlen);
 	sv_insert(lsv, lvoff, lvlen, tmps, len);
+	LvTARGLEN(sv) = sv_len_utf8(sv);
 	SvUTF8_on(lsv);
     }
     else if (lsv && SvUTF8(lsv)) {
 	sv_pos_u2b(lsv, &lvoff, &lvlen);
+	LvTARGLEN(sv) = len;
 	tmps = (char*)bytes_to_utf8((U8*)tmps, &len);
 	sv_insert(lsv, lvoff, lvlen, tmps, len);
 	Safefree(tmps);
     }
-    else
-        sv_insert(lsv, lvoff, lvlen, tmps, len);
+    else {
+	sv_insert(lsv, lvoff, lvlen, tmps, len);
+	LvTARGLEN(sv) = len;
+    }
+
 
     return 0;
 }
@@ -1664,10 +1846,10 @@ Perl_magic_settaint(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_getvec(pTHX_ SV *sv, MAGIC *mg)
 {
-    SV *lsv = LvTARG(sv);
+    SV * const lsv = LvTARG(sv);
 
     if (!lsv) {
-	(void)SvOK_off(sv);
+	SvOK_off(sv);
 	return 0;
     }
 
@@ -1769,17 +1951,18 @@ Perl_magic_killbackrefs(pTHX_ SV *sv, MAGIC *mg)
     SV **svp = AvARRAY(av);
     I32 i = AvFILLp(av);
     while (i >= 0) {
-	if (svp[i] && svp[i] != &PL_sv_undef) {
+	if (svp[i]) {
 	    if (!SvWEAKREF(svp[i]))
 		Perl_croak(aTHX_ "panic: magic_killbackrefs");
 	    /* XXX Should we check that it hasn't changed? */
 	    SvRV(svp[i]) = 0;
-	    (void)SvOK_off(svp[i]);
+	    SvOK_off(svp[i]);
 	    SvWEAKREF_off(svp[i]);
-	    svp[i] = &PL_sv_undef;
+	    svp[i] = Nullsv;
 	}
 	i--;
     }
+    SvREFCNT_dec(av); /* remove extra count added by sv_add_backref() */
     return 0;
 }
 
@@ -1810,7 +1993,7 @@ Perl_magic_setfm(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setuvar(pTHX_ SV *sv, MAGIC *mg)
 {
-    struct ufuncs *uf = (struct ufuncs *)mg->mg_ptr;
+    const struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
 
     if (uf && uf->uf_set)
 	(*uf->uf_set)(aTHX_ uf->uf_index, sv);
@@ -1818,6 +2001,13 @@ Perl_magic_setuvar(pTHX_ SV *sv, MAGIC *mg)
 }
 
 int
+Perl_magic_setregexp(pTHX_ SV *sv, MAGIC *mg)
+{
+    sv_unmagic(sv, PERL_MAGIC_qr);
+    return 0;
+}
+
+int
 Perl_magic_freeregexp(pTHX_ SV *sv, MAGIC *mg)
 {
     regexp *re = (regexp *)mg->mg_obj;
@@ -1867,8 +2057,13 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
 
     case '\004':	/* ^D */
-	PL_debug = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv)) | DEBUG_TOP_FLAG;
+#ifdef DEBUGGING
+	s = SvPV_nolen(sv);
+	PL_debug = get_debug_opts(&s, 0) | DEBUG_TOP_FLAG;
 	DEBUG_x(dump_all());
+#else
+	PL_debug = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv)) | DEBUG_TOP_FLAG;
+#endif
 	break;
     case '\005':  /* ^E */
 	if (*(mg->mg_ptr+1) == '\0') {
@@ -1912,18 +2107,20 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	if (PL_inplace)
 	    Safefree(PL_inplace);
 	if (SvOK(sv))
-	    PL_inplace = savepv(SvPV(sv,len));
+	    PL_inplace = savesvpv(sv);
 	else
 	    PL_inplace = Nullch;
 	break;
     case '\017':	/* ^O */
 	if (*(mg->mg_ptr+1) == '\0') {
-	    if (PL_osname)
+	    if (PL_osname) {
 		Safefree(PL_osname);
-	    if (SvOK(sv))
-		PL_osname = savepv(SvPV(sv,len));
-	    else
 		PL_osname = Nullch;
+	    }
+	    if (SvOK(sv)) {
+		TAINT_PROPER("assigning to $^O");
+		PL_osname = savesvpv(sv);
+	    }
 	}
 	else if (strEQ(mg->mg_ptr, "\017PEN")) {
 	    if (!PL_compiling.cop_io)
@@ -1934,7 +2131,8 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
     case '\020':	/* ^P */
 	PL_perldb = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
-	if (PL_perldb && !PL_DBsingle)
+	if ((PERLDB_SUB || PERLDB_LINE || PERLDB_SUBLINE || PERLDB_ASSERTION)
+		&& !PL_DBsingle)
 	    init_debugger();
 	break;
     case '\024':	/* ^T */
@@ -1963,7 +2161,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 		    STRLEN len, i;
 		    int accumulate = 0 ;
 		    int any_fatals = 0 ;
-		    char * ptr = (char*)SvPV(sv, len) ;
+		    const char * const ptr = (char*)SvPV(sv, len) ;
 		    for (i = 0 ; i < len ; ++i) {
 		        accumulate |= ptr[i] ;
 		        any_fatals |= (ptr[i] & 0xAA) ;
@@ -1997,13 +2195,13 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
     case '^':
 	Safefree(IoTOP_NAME(GvIOp(PL_defoutgv)));
-	IoTOP_NAME(GvIOp(PL_defoutgv)) = s = savepv(SvPV(sv,len));
-	IoTOP_GV(GvIOp(PL_defoutgv)) = gv_fetchpv(s,TRUE, SVt_PVIO);
+	IoTOP_NAME(GvIOp(PL_defoutgv)) = s = savesvpv(sv);
+	IoTOP_GV(GvIOp(PL_defoutgv)) = gv_fetchsv(sv,TRUE, SVt_PVIO);
 	break;
     case '~':
 	Safefree(IoFMT_NAME(GvIOp(PL_defoutgv)));
-	IoFMT_NAME(GvIOp(PL_defoutgv)) = s = savepv(SvPV(sv,len));
-	IoFMT_GV(GvIOp(PL_defoutgv)) = gv_fetchpv(s,TRUE, SVt_PVIO);
+	IoFMT_NAME(GvIOp(PL_defoutgv)) = s = savesvpv(sv);
+	IoFMT_GV(GvIOp(PL_defoutgv)) = gv_fetchsv(sv,TRUE, SVt_PVIO);
 	break;
     case '=':
 	IoPAGE_LEN(GvIOp(PL_defoutgv)) = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
@@ -2033,10 +2231,6 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	    }
 	}
 	break;
-    case '*':
-	i = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
-	PL_multiline = (i != 0);
-	break;
     case '/':
 	SvREFCNT_dec(PL_rs);
 	PL_rs = newSVsv(sv);
@@ -2064,7 +2258,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
     case '#':
 	if (PL_ofmt)
 	    Safefree(PL_ofmt);
-	PL_ofmt = savepv(SvPV(sv,len));
+	PL_ofmt = savesvpv(sv);
 	break;
     case '[':
 	PL_compiling.cop_arybase = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
@@ -2110,9 +2304,14 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 #ifdef HAS_SETRESUID
       (void)setresuid((Uid_t)PL_uid, (Uid_t)-1, (Uid_t)-1);
 #else
-	if (PL_uid == PL_euid)		/* special case $< = $> */
+	if (PL_uid == PL_euid) {		/* special case $< = $> */
+#ifdef PERL_DARWIN
+	    /* workaround for Darwin's setuid peculiarity, cf [perl #24122] */
+	    if (PL_uid != 0 && PerlProc_getuid() == 0)
+		(void)PerlProc_setuid(0);
+#endif
 	    (void)PerlProc_setuid(PL_uid);
-	else {
+	} else {
 	    PL_uid = PerlProc_getuid();
 	    Perl_croak(aTHX_ "setruid() not implemented");
 	}
@@ -2179,7 +2378,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
     case ')':
 #ifdef HAS_SETGROUPS
 	{
-	    char *p = SvPV(sv, len);
+	    const char *p = SvPV(sv, len);
 	    Groups_t gary[NGROUPS];
 
 	    while (isSPACE(*p))
@@ -2263,61 +2462,28 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	     pstat(PSTAT_SETCMD, un, len, 0, 0);
 	}
 #endif
-	if (!PL_origalen) {
-	    s = PL_origargv[0];
-	    s += strlen(s);
-	    /* See if all the arguments are contiguous in memory */
-	    for (i = 1; i < PL_origargc; i++) {
-		if (PL_origargv[i] == s + 1
-#ifdef OS2
-		    || PL_origargv[i] == s + 2
-#endif
-		   )
-		{
-		    ++s;
-		    s += strlen(s);	/* this one is ok too */
-		}
-		else
-		    break;
-	    }
-	    /* can grab env area too? */
-	    if (PL_origenviron
-#ifdef USE_ITHREADS
-		&& PL_curinterp == aTHX
-#endif
-		&& (PL_origenviron[0] == s + 1))
-	    {
-		my_setenv("NoNe  SuCh", Nullch);
-					    /* force copy of environment */
-		for (i = 0; PL_origenviron[i]; i++)
-		    if (PL_origenviron[i] == s + 1) {
-			++s;
-			s += strlen(s);
-		    }
-		    else
-			break;
-	    }
-	    PL_origalen = s - PL_origargv[0];
-	}
+	/* PL_origalen is set in perl_parse(). */
 	s = SvPV_force(sv,len);
-	i = len;
-	if (i >= (I32)PL_origalen) {
-	    i = PL_origalen;
-	    /* don't allow system to limit $0 seen by script */
-	    /* SvCUR_set(sv, i); *SvEND(sv) = '\0'; */
-	    Copy(s, PL_origargv[0], i, char);
-	    s = PL_origargv[0]+i;
-	    *s = '\0';
+	if (len >= (STRLEN)PL_origalen-1) {
+	    /* Longer than original, will be truncated. We assume that
+             * PL_origalen bytes are available. */
+	    Copy(s, PL_origargv[0], PL_origalen-1, char);
 	}
 	else {
-	    Copy(s, PL_origargv[0], i, char);
-	    s = PL_origargv[0]+i;
-	    *s++ = '\0';
-	    while (++i < (I32)PL_origalen)
-		*s++ = '\0';
-	    for (i = 1; i < PL_origargc; i++)
-		PL_origargv[i] = Nullch;
-	}
+	    /* Shorter than original, will be padded. */
+	    Copy(s, PL_origargv[0], len, char);
+	    PL_origargv[0][len] = 0;
+	    memset(PL_origargv[0] + len + 1,
+		   /* Is the space counterintuitive?  Yes.
+		    * (You were expecting \0?)  
+		    * Does it work?  Seems to.  (In Linux 2.4.20 at least.)
+		    * --jhi */
+		   (int)' ',
+		   PL_origalen - len - 1);
+	}
+	PL_origargv[0][PL_origalen-1] = 0;
+	for (i = 1; i < PL_origargc; i++)
+	    PL_origargv[i] = 0;
 	UNLOCK_DOLLARZERO_MUTEX;
 	break;
 #endif
@@ -2326,11 +2492,11 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 }
 
 I32
-Perl_whichsig(pTHX_ char *sig)
+Perl_whichsig(pTHX_ const char *sig)
 {
     register char **sigv;
 
-    for (sigv = PL_sig_name+1; *sigv; sigv++)
+    for (sigv = PL_sig_name; *sigv; sigv++)
 	if (strEQ(sig,*sigv))
 	    return PL_sig_num[sigv - PL_sig_name];
 #ifdef SIGCLD
@@ -2341,7 +2507,7 @@ Perl_whichsig(pTHX_ char *sig)
     if (strEQ(sig,"CLD"))
 	return SIGCHLD;
 #endif
-    return 0;
+    return -1;
 }
 
 #if !defined(PERL_IMPLICIT_CONTEXT)
@@ -2369,8 +2535,6 @@ Perl_sighandler(int sig)
 	flags |= 1;
     if (PL_markstack_ptr < PL_markstack_max - 2)
 	flags |= 4;
-    if (PL_retstack_ix < PL_retstack_max - 2)
-	flags |= 8;
     if (PL_scopestack_ix < PL_scopestack_max - 3)
 	flags |= 16;
 
@@ -2388,10 +2552,6 @@ Perl_sighandler(int sig)
     }
     if (flags & 4)
 	PL_markstack_ptr++;		/* Protect mark. */
-    if (flags & 8) {
-	PL_retstack_ix++;
-	PL_retstack[PL_retstack_ix] = NULL;
-    }
     if (flags & 16)
 	PL_scopestack_ix += 1;
     /* sv_2cv is too complicated, try a simpler variant first: */
@@ -2442,18 +2602,16 @@ Perl_sighandler(int sig)
 #else
 	/* Not clear if this will work */
 	(void)rsignal(sig, SIG_IGN);
-	(void)rsignal(sig, &Perl_csighandler);
+	(void)rsignal(sig, PL_csighandlerp);
 #endif
 #endif /* !PERL_MICRO */
-	Perl_die(aTHX_ Nullformat);
+	DieNull;
     }
 cleanup:
     if (flags & 1)
 	PL_savestack_ix -= 8; /* Unprotect save in progress. */
     if (flags & 4)
 	PL_markstack_ptr--;
-    if (flags & 8)
-	PL_retstack_ix--;
     if (flags & 16)
 	PL_scopestack_ix -= 1;
     if (flags & 64)
@@ -2467,7 +2625,7 @@ cleanup:
 
 
 static void
-restore_magic(pTHX_ void *p)
+restore_magic(pTHX_ const void *p)
 {
     MGS* mgs = SSPTR(PTR2IV(p), MGS*);
     SV* sv = mgs->mgs_sv;
@@ -2477,6 +2635,13 @@ restore_magic(pTHX_ void *p)
 
     if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv))
     {
+#ifdef PERL_COPY_ON_WRITE
+	/* While magic was saved (and off) sv_setsv may well have seen
+	   this SV as a prime candidate for COW.  */
+	if (SvIsCOW(sv))
+	    sv_force_normal(sv);
+#endif
+
 	if (mgs->mgs_flags)
 	    SvFLAGS(sv) |= mgs->mgs_flags;
 	else
@@ -2508,9 +2673,9 @@ restore_magic(pTHX_ void *p)
 }
 
 static void
-unwind_handler_stack(pTHX_ void *p)
+unwind_handler_stack(pTHX_ const void *p)
 {
-    U32 flags = *(U32*)p;
+    const U32 flags = *(U32*)p;
 
     if (flags & 1)
 	PL_savestack_ix -= 5; /* Unprotect save in progress. */