Rewrite sv_catsv to pass SV_CAT* flags to sv_catpvn

(Both functions actually end with _flags, but I’m trying to keep the
first line short.)

Now that sv_catpvn_flags has this functionality (as of c682ebef86),
sv_catsv can use it, which avoids creating an extra SV for the
utf8+bytes case and removes some duplicate logic.

Also, one code path in sv_utf8_upgrade_flags_grow was ignore the
_grow, causing crashes after the sv_catsv change, so this patch fixes
that, too.

Also, sv_catpvn_flags was not allocating a byte for the trailing
nul, which was entirely my fault (c682ebef86).  So that is hereby
fixed as well.

diff --git a/sv.c b/sv.c
index e92ed2b..88b93c6 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -3264,6 +3264,7 @@ Perl_sv_utf8_upgrade_flags_grow(pTHX_ register SV *const sv, const I32 flags, ST
        /* utf8 conversion not needed because all are invariants.  Mark as
         * UTF-8 even if no variant - saves scanning loop */
        SvUTF8_on(sv);
+       if (extra) SvGROW(sv, SvCUR(sv) + extra);
        return SvCUR(sv);
 
 must_be_utf8:
@@ -4998,7 +4999,7 @@ Perl_sv_catpvn_flags(pTHX_ register SV *const dsv, register const char *sstr, re
 
     if (!(flags & SV_CATBYTES) || !SvUTF8(dsv)) {
       if (flags & SV_CATUTF8 && !SvUTF8(dsv)) {
-        sv_utf8_upgrade_flags_grow(dsv, 0, slen);
+        sv_utf8_upgrade_flags_grow(dsv, 0, slen + 1);
         dlen = SvCUR(dsv);
       }
       else SvGROW(dsv, dlen + slen + 1);
@@ -5017,7 +5018,7 @@ Perl_sv_catpvn_flags(pTHX_ register SV *const dsv, register const char *sstr, re
           bytes *and* utf8, which would indicate a bug elsewhere. */
        assert(sstr != dstr);
 
-       SvGROW(dsv, dlen + slen * 2);
+       SvGROW(dsv, dlen + slen * 2 + 1);
        d = (U8 *)SvPVX(dsv) + dlen;
 
        while (sstr < send) {
@@ -5065,33 +5066,10 @@ Perl_sv_catsv_flags(pTHX_ SV *const dsv, register SV *const ssv, const I32 flags
        STRLEN slen;
        const char *spv = SvPV_flags_const(ssv, slen, flags);
        if (spv) {
-           /*  sutf8 and dutf8 were type bool, but under USE_ITHREADS,
-               gcc version 2.95.2 20000220 (Debian GNU/Linux) for
-               Linux xxx 2.2.17 on sparc64 with gcc -O2, we erroneously
-               get dutf8 = 0x20000000, (i.e.  SVf_UTF8) even though
-               dsv->sv_flags doesn't have that bit set.
-               Andy Dougherty  12 Oct 2001
-           */
-           const I32 sutf8 = DO_UTF8(ssv);
-           I32 dutf8;
-
            if (SvGMAGICAL(dsv) && (flags & SV_GMAGIC))
                mg_get(dsv);
-           dutf8 = DO_UTF8(dsv);
-
-           if (dutf8 != sutf8) {
-               if (dutf8) {
-                   /* Not modifying source SV, so taking a temporary copy. */
-                   SV* const csv = newSVpvn_flags(spv, slen, SVs_TEMP);
-
-                   sv_utf8_upgrade(csv);
-                   spv = SvPV_const(csv, slen);
-               }
-               else
-                   /* Leave enough space for the cat that's about to happen */
-                   sv_utf8_upgrade_flags_grow(dsv, 0, slen);
-           }
-           sv_catpvn_nomg(dsv, spv, slen);
+           sv_catpvn_flags(dsv, spv, slen,
+                           DO_UTF8(ssv) ? SV_CATUTF8 : SV_CATBYTES);
        }
     }
     if (flags & SV_SMAGIC)