Move SvPV consting, remove an n_a, and correct one error in Move()

p4raw-id: //depot/perl@24798

5 files changed, 71 insertions, 70 deletions

diff --git a/doio.c b/doio.c
index 79ca1fd174..cafa43566a 100644
--- a/doio.c
+++ b/doio.c
@@ -852,7 +852,8 @@ Perl_nextargv(pTHX_ register GV *gv)
 		    do_close(gv,FALSE);
 		    (void)PerlLIO_unlink(SvPVX_const(sv));
 		    (void)PerlLIO_rename(PL_oldname,SvPVX_const(sv));
-		    do_open(gv,SvPVX(sv),SvCUR(sv),PL_inplace!=0,O_RDONLY,0,Nullfp);
+		    do_open(gv,(char*)SvPVX_const(sv),SvCUR(sv),PL_inplace!=0,
+			    O_RDONLY,0,Nullfp);
 #endif /* DOSISH */
 #else
 		    (void)UNLINK(SvPVX_const(sv));
@@ -888,11 +889,12 @@ Perl_nextargv(pTHX_ register GV *gv)
 		sv_catpvn(sv,PL_oldname,oldlen);
 		SETERRNO(0,0);		/* in case sprintf set errno */
 #ifdef VMS
-		if (!do_open(PL_argvoutgv,SvPVX(sv),SvCUR(sv),PL_inplace!=0,
-                 O_WRONLY|O_CREAT|O_TRUNC,0,Nullfp))
+		if (!do_open(PL_argvoutgv,(char*)SvPVX_const(sv),SvCUR(sv),
+			     PL_inplace!=0,O_WRONLY|O_CREAT|O_TRUNC,0,Nullfp))
 #else
-		if (!do_open(PL_argvoutgv,SvPVX(sv),SvCUR(sv),PL_inplace!=0,
-			     O_WRONLY|O_CREAT|OPEN_EXCL,0666,Nullfp))
+		    if (!do_open(PL_argvoutgv,(char*)SvPVX_const(sv),SvCUR(sv),
+			     PL_inplace!=0,O_WRONLY|O_CREAT|OPEN_EXCL,0666,
+			     Nullfp))
 #endif
 		{
 		    if (ckWARN_d(WARN_INPLACE))	
@@ -2056,14 +2058,14 @@ Perl_do_ipcctl(pTHX_ I32 optype, SV **mark, SV **sp)
 
     if (infosize)
     {
-	STRLEN len;
 	if (getinfo)
 	{
-	    SvPV_force(astr, len);
+	    SvPV_force_nolen(astr);
 	    a = SvGROW(astr, infosize+1);
 	}
 	else
 	{
+	    STRLEN len;
 	    a = SvPV(astr, len);
 	    if (len != infosize)
 		Perl_croak(aTHX_ "Bad arg length for %s, is %lu, should be %ld",
@@ -2121,7 +2123,7 @@ Perl_do_msgsnd(pTHX_ SV **mark, SV **sp)
 {
 #ifdef HAS_MSG
     SV *mstr;
-    char *mbuf;
+    const char *mbuf;
     I32 msize, flags;
     STRLEN len;
     const I32 id = SvIVx(*++mark);
@@ -2129,7 +2131,7 @@ Perl_do_msgsnd(pTHX_ SV **mark, SV **sp)
 
     mstr = *++mark;
     flags = SvIVx(*++mark);
-    mbuf = SvPV(mstr, len);
+    mbuf = SvPV_const(mstr, len);
     if ((msize = len - sizeof(long)) < 0)
 	Perl_croak(aTHX_ "Arg too short for msgsnd");
     SETERRNO(0,0);
@@ -2147,7 +2149,6 @@ Perl_do_msgrcv(pTHX_ SV **mark, SV **sp)
     char *mbuf;
     long mtype;
     I32 msize, flags, ret;
-    STRLEN len;
     const I32 id = SvIVx(*++mark);
     (void)sp;
 
@@ -2158,7 +2159,7 @@ Perl_do_msgrcv(pTHX_ SV **mark, SV **sp)
     msize = SvIVx(*++mark);
     mtype = (long)SvIVx(*++mark);
     flags = SvIVx(*++mark);
-    SvPV_force(mstr, len);
+    SvPV_force_nolen(mstr);
     mbuf = SvGROW(mstr, sizeof(long)+msize+1);
 
     SETERRNO(0,0);
@@ -2182,13 +2183,13 @@ Perl_do_semop(pTHX_ SV **mark, SV **sp)
 {
 #ifdef HAS_SEM
     SV *opstr;
-    char *opbuf;
+    const char *opbuf;
     STRLEN opsize;
     const I32 id = SvIVx(*++mark);
     (void)sp;
 
     opstr = *++mark;
-    opbuf = SvPV(opstr, opsize);
+    opbuf = SvPV_const(opstr, opsize);
     if (opsize < 3 * SHORTSIZE
 	|| (opsize % (3 * SHORTSIZE))) {
 	SETERRNO(EINVAL,LIB_INVARG);
@@ -2237,7 +2238,6 @@ Perl_do_shmio(pTHX_ I32 optype, SV **mark, SV **sp)
     SV *mstr;
     char *shm;
     I32 mpos, msize;
-    STRLEN len;
     struct shmid_ds shmds;
     const I32 id = SvIVx(*++mark);
     (void)sp;
@@ -2260,7 +2260,7 @@ Perl_do_shmio(pTHX_ I32 optype, SV **mark, SV **sp)
 	/* suppress warning when reading into undef var (tchrist 3/Mar/00) */
 	if (! SvOK(mstr))
 	    sv_setpvn(mstr, "", 0);
-	SvPV_force(mstr, len);
+	SvPV_force_nolen(mstr);
 	mbuf = SvGROW(mstr, msize+1);
 
 	Copy(shm + mpos, mbuf, msize, char);
@@ -2274,8 +2274,9 @@ Perl_do_shmio(pTHX_ I32 optype, SV **mark, SV **sp)
     }
     else {
 	I32 n;
+	STRLEN len;
 
-	const char *mbuf = SvPV(mstr, len);
+	const char *mbuf = SvPV_const(mstr, len);
 	if ((n = len) > msize)
 	    n = msize;
 	Copy(mbuf, shm + mpos, n, char);
@@ -2433,7 +2434,7 @@ Perl_start_glob (pTHX_ SV *tmpglob, IO *io)
 #endif /* !CSH */
 #endif /* !DOSISH */
 #endif /* MACOS_TRADITIONAL */
-    (void)do_open(PL_last_in_gv, SvPVX(tmpcmd), SvCUR(tmpcmd),
+    (void)do_open(PL_last_in_gv, (char*)SvPVX_const(tmpcmd), SvCUR(tmpcmd),
 		  FALSE, O_RDONLY, 0, Nullfp);
     fp = IoIFP(io);
 #endif /* !VMS */
diff --git a/doop.c b/doop.c
index b17da1ad29..73ccdcdf96 100644
--- a/doop.c
+++ b/doop.c
@@ -395,8 +395,8 @@ S_do_trans_simple_utf8(pTHX_ SV *sv)
 STATIC I32
 S_do_trans_count_utf8(pTHX_ SV *sv)
 {
-    U8 *s;
-    U8 *start = 0, *send;
+    const U8 *s;
+    const U8 *start = 0, *send;
     I32 matches = 0;
     STRLEN len;
 
@@ -407,7 +407,7 @@ S_do_trans_count_utf8(pTHX_ SV *sv)
     const UV extra = none + 1;
     U8 hibit = 0;
 
-    s = (U8*)SvPV(sv, len);
+    s = (const U8*)SvPV_const(sv, len);
     if (!SvUTF8(sv)) {
 	const U8 *t = s;
 	const U8 *e = s + len;
@@ -1071,7 +1071,7 @@ Perl_do_chomp(pTHX_ register SV *sv)
 	}
 	else {
 	    STRLEN rslen, rs_charlen;
-	    char *rsptr = SvPV(PL_rs, rslen);
+	    const char *rsptr = SvPV_const(PL_rs, rslen);
 
 	    rs_charlen = SvUTF8(PL_rs)
 		? sv_len_utf8(PL_rs)
@@ -1098,7 +1098,7 @@ Perl_do_chomp(pTHX_ register SV *sv)
 		     * Do not recode PL_rs as a side-effect. */
 		   svrecode = newSVpvn(rsptr, rslen);
 		   sv_recode_to_utf8(svrecode, PL_encoding);
-		   rsptr = SvPV(svrecode, rslen);
+		   rsptr = SvPV_const(svrecode, rslen);
 		   rs_charlen = sv_len_utf8(svrecode);
 		}
 		else {
diff --git a/dump.c b/dump.c
index fed067df6d..ddeacf4da3 100644
--- a/dump.c
+++ b/dump.c
@@ -406,7 +406,7 @@ sequence(pTHX_ register const OP *o)
 {
     dVAR;
     SV      *op;
-    char    *key;
+    const char *key;
     STRLEN   len;
     const OP *oldop = 0;
     OP      *l;
@@ -415,13 +415,13 @@ sequence(pTHX_ register const OP *o)
 	return;
 
     op = newSVuv(PTR2UV(o));
-    key = SvPV(op, len);
+    key = SvPV_const(op, len);
     if (hv_exists(Sequence, key, len))
 	return;
 
     for (; o; o = o->op_next) {
 	op = newSVuv(PTR2UV(o));
-	key = SvPV(op, len);
+	key = SvPV_const(op, len);
 	if (hv_exists(Sequence, key, len))
 	    break;
 
@@ -501,11 +501,11 @@ sequence_num(pTHX_ const OP *o)
     dVAR;
     SV     *op,
           **seq;
-    char   *key;
+    const char *key;
     STRLEN  len;
     if (!o) return 0;
     op = newSVuv(PTR2UV(o));
-    key = SvPV(op, len);
+    key = SvPV_const(op, len);
     seq = hv_fetch(Sequence, key, len, 0);
     return seq ? SvUV(*seq): 0;
 }
@@ -1452,7 +1452,7 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
 		U32 hash = HeHASH(he);
 
 		keysv = hv_iterkeysv(he);
-		keypv = SvPV(keysv, len);
+		keypv = SvPV_const(keysv, len);
 		elt = hv_iterval(hv, he);
 		Perl_dump_indent(aTHX_ level+1, file, "Elt %s ", pv_display(d, keypv, len, 0, pvlim));
 		if (SvUTF8(keysv))
@@ -1467,7 +1467,7 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
 	break;
     case SVt_PVCV:
 	if (SvPOK(sv))
-	    Perl_dump_indent(aTHX_ level, file, "  PROTOTYPE = \"%s\"\n", SvPV_nolen(sv));
+	    Perl_dump_indent(aTHX_ level, file, "  PROTOTYPE = \"%s\"\n", SvPV_nolen_const(sv));
 	/* FALL THROUGH */
     case SVt_PVFM:
 	do_hv_dump(level, file, "  COMP_STASH", CvSTASH(sv));
@@ -1620,7 +1620,7 @@ Perl_debop(pTHX_ const OP *o)
 	if (cGVOPo_gv) {
 	    SV *sv = NEWSV(0,0);
 	    gv_fullname3(sv, cGVOPo_gv, Nullch);
-	    PerlIO_printf(Perl_debug_log, "(%s)", SvPV_nolen(sv));
+	    PerlIO_printf(Perl_debug_log, "(%s)", SvPV_nolen_const(sv));
 	    SvREFCNT_dec(sv);
 	}
 	else
@@ -1640,7 +1640,7 @@ Perl_debop(pTHX_ const OP *o)
         } else
             sv = Nullsv;
         if (sv)
-           PerlIO_printf(Perl_debug_log, "(%s)", SvPV_nolen(sv));
+           PerlIO_printf(Perl_debug_log, "(%s)", SvPV_nolen_const(sv));
         else
            PerlIO_printf(Perl_debug_log, "[%"UVuf"]", (UV)o->op_targ);
 	}
diff --git a/op.c b/op.c
index 12a8c25f57..f165c25e0c 100644
--- a/op.c
+++ b/op.c
@@ -2491,7 +2491,7 @@ Perl_pmtrans(pTHX_ OP *o, OP *expr, OP *repl)
 	    t = uvuni_to_utf8_flags(tmpbuf, 0x7fffffff,
 				    UNICODE_ALLOW_SUPER);
 	    sv_catpvn(transv, (char*)tmpbuf, t - tmpbuf);
-	    t = (U8*)SvPVX(transv);
+	    t = (const U8*)SvPVX_const(transv);
 	    tlen = SvCUR(transv);
 	    tend = t + tlen;
 	    Safefree(cp);
@@ -5507,7 +5507,7 @@ Perl_ck_fun(pTHX_ OP *o)
 					   
 				      }
 				      if (tmpstr) {
-					   name = SvPV(tmpstr, len);
+					   name = SvPV_const(tmpstr, len);
 					   sv_2mortal(tmpstr);
 				      }
 				 }
@@ -6812,13 +6812,13 @@ Perl_peep(pTHX_ register OP *o)
 	    fields = (GV**)hv_fetch(SvSTASH(lexname), "FIELDS", 6, FALSE);
 	    if (!fields || !GvHV(*fields))
 		break;
-	    key = SvPV(*svp, keylen);
+	    key = SvPV_const(*svp, keylen);
 	    if (!hv_fetch(GvHV(*fields), key,
 			SvUTF8(*svp) ? -(I32)keylen : keylen, FALSE))
 	    {
 		Perl_croak(aTHX_ "No such class field \"%s\" " 
 			   "in variable %s of type %s", 
-		      key, SvPV_nolen(lexname), HvNAME_get(SvSTASH(lexname)));
+		      key, SvPV_nolen_const(lexname), HvNAME_get(SvSTASH(lexname)));
 	    }
 
             break;
@@ -6829,7 +6829,7 @@ Perl_peep(pTHX_ register OP *o)
 	    SV *lexname;
 	    GV **fields;
 	    SV **svp;
-	    char *key;
+	    const char *key;
 	    STRLEN keylen;
 	    SVOP *first_key_op, *key_op;
 
@@ -6869,7 +6869,7 @@ Perl_peep(pTHX_ register OP *o)
 		if (key_op->op_type != OP_CONST)
 		    continue;
 		svp = cSVOPx_svp(key_op);
-		key = SvPV(*svp, keylen);
+		key = SvPV_const(*svp, keylen);
 		if (!hv_fetch(GvHV(*fields), key, 
 			    SvUTF8(*svp) ? -(I32)keylen : keylen, FALSE))
 		{
diff --git a/sv.c b/sv.c
index 6f93a3f84c..81f407c25c 100644
--- a/sv.c
+++ b/sv.c
@@ -765,7 +765,7 @@ S_varname(pTHX_ GV *gv, const char *gvtype, PADOFFSET targ,
 	av = (AV*)(*av_fetch(CvPADLIST(cv), 0, FALSE));
 	sv = *av_fetch(av, targ, FALSE);
 	/* SvLEN in a pad name is not to be trusted */
-	str = SvPV(sv,len);
+	str = SvPV_const(sv,len);
 	sv_setpvn(name, str, len);
     }
 
@@ -1120,7 +1120,7 @@ Perl_report_uninit(pTHX_ SV* uninit_sv)
 		sv_insert(varname, 0, 0, " ", 1);
 	}
 	Perl_warner(aTHX_ packWARN(WARN_UNINITIALIZED), PL_warn_uninit,
-		varname ? SvPV_nolen(varname) : "",
+		varname ? SvPV_nolen_const(varname) : "",
 		" in ", OP_DESC(PL_op));
     }
     else
@@ -2024,11 +2024,11 @@ Perl_sv_grow(pTHX_ register SV *sv, register STRLEN newlen)
 	sv_unref(sv);
     if (SvTYPE(sv) < SVt_PV) {
 	sv_upgrade(sv, SVt_PV);
-	s = SvPVX(sv);
+	s = SvPVX_mutable(sv);
     }
     else if (SvOOK(sv)) {	/* pv is offset? */
 	sv_backoff(sv);
-	s = SvPVX(sv);
+	s = SvPVX_mutable(sv);
 	if (newlen > SvLEN(sv))
 	    newlen += 10 * (newlen - SvCUR(sv)); /* avoid copy each time */
 #ifdef HAS_64K_LIMIT
@@ -2043,7 +2043,7 @@ Perl_sv_grow(pTHX_ register SV *sv, register STRLEN newlen)
 	newlen = PERL_STRLEN_ROUNDUP(newlen);
 	if (SvLEN(sv) && s) {
 #ifdef MYMALLOC
-	    const STRLEN l = malloced_size((void*)SvPVX(sv));
+	    const STRLEN l = malloced_size((void*)SvPVX_const(sv));
 	    if (newlen <= l) {
 		SvLEN_set(sv, l);
 		return s;
@@ -3441,6 +3441,7 @@ Perl_sv_2pv_flags(pTHX_ register SV *sv, STRLEN *lp, I32 flags)
             register const char *typestr;
             if (SvAMAGIC(sv) && (tmpstr=AMG_CALLun(sv,string)) &&
                 (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
+		/* FIXME - figure out best way to pass context inwards.  */
                 char *pv = lp ? SvPV(tmpstr, *lp) : SvPV_nolen(tmpstr);
                 if (SvUTF8(tmpstr))
                     SvUTF8_on(sv);
@@ -3916,9 +3917,9 @@ Perl_sv_utf8_upgrade_flags(pTHX_ register SV *sv, I32 flags)
 	 * had a FLAG in SVs to signal if there are any hibit
 	 * chars in the PV.  Given that there isn't such a flag
 	 * make the loop as fast as possible. */
-	U8 *s = (U8 *) SvPVX(sv);
-	U8 *e = (U8 *) SvEND(sv);
-	U8 *t = s;
+	const U8 *s = (U8 *) SvPVX_const(sv);
+	const U8 *e = (U8 *) SvEND(sv);
+	const U8 *t = s;
 	int hibit = 0;
 	
 	while (t < e) {
@@ -3928,11 +3929,11 @@ Perl_sv_utf8_upgrade_flags(pTHX_ register SV *sv, I32 flags)
 	}
 	if (hibit) {
 	    STRLEN len = SvCUR(sv) + 1; /* Plus the \0 */
-	    s = bytes_to_utf8((U8*)s, &len);
+	    char *recoded = bytes_to_utf8((U8*)s, &len);
 
 	    SvPV_free(sv); /* No longer using what was there before. */
 
-	    SvPV_set(sv, (char*)s);
+	    SvPV_set(sv, recoded);
 	    SvCUR_set(sv, len - 1);
 	    SvLEN_set(sv, len); /* No longer know the real size. */
 	}
@@ -4024,8 +4025,8 @@ bool
 Perl_sv_utf8_decode(pTHX_ register SV *sv)
 {
     if (SvPOKp(sv)) {
-        U8 *c;
-        U8 *e;
+        const U8 *c;
+        const U8 *e;
 
 	/* The octets may have got themselves encoded - get them back as
 	 * bytes
@@ -4036,10 +4037,10 @@ Perl_sv_utf8_decode(pTHX_ register SV *sv)
         /* it is actually just a matter of turning the utf8 flag on, but
          * we want to make sure everything inside is valid utf8 first.
          */
-        c = (U8 *) SvPVX(sv);
+        c = (const U8 *) SvPVX_const(sv);
 	if (!is_utf8_string(c, SvCUR(sv)+1))
 	    return FALSE;
-        e = (U8 *) SvEND(sv);
+        e = (const U8 *) SvEND(sv);
         while (c < e) {
 	    U8 ch = *c++;
             if (!UTF8_IS_INVARIANT(ch)) {
@@ -4373,7 +4374,8 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
 			    }
 			    if (!intro)
 				cv_ckproto(cv, (GV*)dstr,
-					SvPOK(sref) ? SvPVX(sref) : Nullch);
+					   SvPOK(sref)
+					   ? SvPVX_const(sref) : Nullch);
 			}
 			GvCV(dstr) = (CV*)sref;
 			GvCVGEN(dstr) = 0; /* Switch off cacheness. */
@@ -5180,7 +5182,7 @@ Perl_sv_catsv_flags(pTHX_ SV *dsv, register SV *ssv, I32 flags)
 		SV* csv = sv_2mortal(newSVpvn(spv, slen));
 
 		sv_utf8_upgrade(csv);
-		spv = SvPV(csv, slen);
+		spv = SvPV_const(csv, slen);
 	    }
 	    else
 		sv_utf8_upgrade_nomg(dsv);
@@ -5690,7 +5692,7 @@ Perl_sv_insert(pTHX_ SV *bigstr, STRLEN offset, STRLEN len, const char *little,
     (void)SvPOK_only_UTF8(bigstr);
     if (offset + len > curlen) {
 	SvGROW(bigstr, offset+len+1);
-	Zero(SvPVX_const(bigstr)+curlen, offset+len-curlen, char);
+	Zero(SvPVX(bigstr)+curlen, offset+len-curlen, char);
 	SvCUR_set(bigstr, offset+len);
     }
 
@@ -5967,7 +5969,7 @@ Perl_sv_clear(pTHX_ register SV *sv)
       freescalar:
 	/* Don't bother with SvOOK_off(sv); as we're only going to free it.  */
 	if (SvOOK(sv)) {
-	    SvPV_set(sv, SvPVX(sv) - SvIVX(sv));
+	    SvPV_set(sv, SvPVX_mutable(sv) - SvIVX(sv));
 	    /* Don't even bother with turning off the OOK flag.  */
 	}
 	/* FALL THROUGH */
@@ -6631,12 +6633,12 @@ Perl_sv_eq(pTHX_ register SV *sv1, register SV *sv2)
 	      if (SvUTF8(sv1)) {
 		   svrecode = newSVpvn(pv2, cur2);
 		   sv_recode_to_utf8(svrecode, PL_encoding);
-		   pv2 = SvPV(svrecode, cur2);
+		   pv2 = SvPV_const(svrecode, cur2);
 	      }
 	      else {
 		   svrecode = newSVpvn(pv1, cur1);
 		   sv_recode_to_utf8(svrecode, PL_encoding);
-		   pv1 = SvPV(svrecode, cur1);
+		   pv1 = SvPV_const(svrecode, cur1);
 	      }
 	      /* Now both are in UTF-8. */
 	      if (cur1 != cur2) {
@@ -6724,7 +6726,7 @@ Perl_sv_cmp(pTHX_ register SV *sv1, register SV *sv2)
 	    if (PL_encoding) {
 		 svrecode = newSVpvn(pv2, cur2);
 		 sv_recode_to_utf8(svrecode, PL_encoding);
-		 pv2 = SvPV(svrecode, cur2);
+		 pv2 = SvPV_const(svrecode, cur2);
 	    }
 	    else {
 		 pv2 = tpv = (char*)bytes_to_utf8((const U8*)pv2, &cur2);
@@ -6734,7 +6736,7 @@ Perl_sv_cmp(pTHX_ register SV *sv1, register SV *sv2)
 	    if (PL_encoding) {
 		 svrecode = newSVpvn(pv1, cur1);
 		 sv_recode_to_utf8(svrecode, PL_encoding);
-		 pv1 = SvPV(svrecode, cur1);
+		 pv1 = SvPV_const(svrecode, cur1);
 	    }
 	    else {
 		 pv1 = tpv = (char*)bytes_to_utf8((const U8*)pv1, &cur1);
@@ -6848,12 +6850,13 @@ Perl_sv_collxfrm(pTHX_ SV *sv, STRLEN *nxp)
 
     mg = SvMAGICAL(sv) ? mg_find(sv, PERL_MAGIC_collxfrm) : (MAGIC *) NULL;
     if (!mg || !mg->mg_ptr || *(U32*)mg->mg_ptr != PL_collation_ix) {
-	char *s, *xf;
+	const char *s;
+	char *xf;
 	STRLEN len, xlen;
 
 	if (mg)
 	    Safefree(mg->mg_ptr);
-	s = SvPV(sv, len);
+	s = SvPV_const(sv, len);
 	if ((xf = mem_collxfrm(s, len, &xlen))) {
 	    if (SvREADONLY(sv)) {
 		SAVEFREEPV(xf);
@@ -7001,7 +7004,7 @@ Perl_sv_gets(pTHX_ register SV *sv, register PerlIO *fp, I32 append)
 		    Perl_croak(aTHX_ "Wide character in $/");
 		}
 	    }
-	    rsptr = SvPV(PL_rs, rslen);
+	    rsptr = SvPV_const(PL_rs, rslen);
 	}
     }
 
@@ -8214,12 +8217,10 @@ Perl_sv_nv(pTHX_ register SV *sv)
 char *
 Perl_sv_pv(pTHX_ SV *sv)
 {
-    STRLEN n_a;
-
     if (SvPOK(sv))
 	return SvPVX(sv);
 
-    return sv_2pv(sv, &n_a);
+    return sv_2pv(sv, 0);
 }
 
 /*
@@ -10119,7 +10120,7 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 	     else {
 		  SV *nsv = sv_2mortal(newSVpvn(eptr, elen));
 		  sv_utf8_upgrade(nsv);
-		  eptr = SvPVX(nsv);
+		  eptr = SvPVX_const(nsv);
 		  elen = SvCUR(nsv);
 	     }
 	     SvGROW(sv, SvCUR(sv) + elen + 1);
@@ -12476,7 +12477,7 @@ Perl_sv_recode_to_utf8(pTHX_ SV *sv, SV *encoding)
     if (SvPOK(sv) && !SvUTF8(sv) && !IN_BYTES && SvROK(encoding)) {
 	SV *uni;
 	STRLEN len;
-	char *s;
+	const char *s;
 	dSP;
 	ENTER;
 	SAVETMPS;
@@ -12500,12 +12501,11 @@ Perl_sv_recode_to_utf8(pTHX_ SV *sv, SV *encoding)
 	SPAGAIN;
 	uni = POPs;
 	PUTBACK;
-	s = SvPV(uni, len);
+	s = SvPV_const(uni, len);
 	if (s != SvPVX_const(sv)) {
 	    SvGROW(sv, len + 1);
-	    Move(s, SvPVX_const(sv), len, char);
+	    Move(s, SvPVX(sv), len + 1, char);
 	    SvCUR_set(sv, len);
-	    SvPVX(sv)[len] = 0;	
 	}
 	FREETMPS;
 	LEAVE;