lcfirst/ucfist plus an 8 bit locale could mangle UTF-8 values

returned by overloaded stringification.

p4raw-id: //depot/perl@28013

diff --git a/pp.c b/pp.c
index 86299ac..b937e0a 100644 (file)
--- a/pp.c
+++ b/pp.c
@@ -3413,28 +3413,64 @@ PP(pp_ucfirst)
 {
     dVAR;
     dSP;
-    SV *sv = TOPs;
-    const U8 *s;
+    SV *source = TOPs;
     STRLEN slen;
+    STRLEN need;
+    SV *dest;
+    bool inplace = TRUE;
+    bool doing_utf8;
     const int op_type = PL_op->op_type;
+    const U8 *s;
+    U8 *d;
+    U8 tmpbuf[UTF8_MAXBYTES_CASE+1];
+    STRLEN ulen;
+    STRLEN tculen;
 
-    SvGETMAGIC(sv);
-    if (DO_UTF8(sv) &&
-       (s = (const U8*)SvPV_nomg_const(sv, slen)) && slen &&
-       UTF8_IS_START(*s)) {
-       U8 tmpbuf[UTF8_MAXBYTES_CASE+1];
-       STRLEN ulen;
-       STRLEN tculen;
+    SvGETMAGIC(source);
+    if (SvOK(source)) {
+       s = (const U8*)SvPV_nomg_const(source, slen);
+    } else {
+       s = "";
+       slen = 0;
+    }
 
+    if (slen && DO_UTF8(source) && UTF8_IS_START(*s)) {
+       doing_utf8 = TRUE;
        utf8_to_uvchr(s, &ulen);
        if (op_type == OP_UCFIRST) {
            toTITLE_utf8(s, tmpbuf, &tculen);
        } else {
            toLOWER_utf8(s, tmpbuf, &tculen);
        }
+       /* If the two differ, we definately cannot do inplace.  */
+       inplace = ulen == tculen;
+       need = slen + 1 - ulen + tculen;
+    } else {
+       doing_utf8 = FALSE;
+       need = slen + 1;
+    }
+
+    if (SvPADTMP(source) && !SvREADONLY(source) && inplace) {
+       /* We can convert in place.  */
+
+       dest = source;
+       s = d = (U8*)SvPV_force_nomg(source, slen);
+    } else {
+       dTARGET;
 
-       if (!SvPADTMP(sv) || SvREADONLY(sv) || ulen != tculen) {
-           dTARGET;
+       dest = TARG;
+
+       SvUPGRADE(dest, SVt_PV);
+       d = SvGROW(dest, need);
+       (void)SvPOK_only(dest);
+
+       SETs(dest);
+
+       inplace = FALSE;
+    }
+
+    if (doing_utf8) {
+       if(!inplace) {
            /* slen is the byte length of the whole SV.
             * ulen is the byte length of the original Unicode character
             * stored as UTF-8 at s.
@@ -3442,40 +3478,41 @@ PP(pp_ucfirst)
             * lowercased) Unicode character stored as UTF-8 at tmpbuf.
             * We first set the result to be the titlecased (/lowercased)
             * character, and then append the rest of the SV data. */
-           sv_setpvn(TARG, (char*)tmpbuf, tculen);
+           sv_setpvn(dest, (char*)tmpbuf, tculen);
            if (slen > ulen)
-               sv_catpvn(TARG, (char*)(s + ulen), slen - ulen);
-           SvUTF8_on(TARG);
-           sv = TARG;
-           SETs(sv);
+               sv_catpvn(dest, (char*)(s + ulen), slen - ulen);
+           SvUTF8_on(dest);
        }
        else {
-           s = (U8*)SvPV_force_nomg(sv, slen);
-           Copy(tmpbuf, s, tculen, U8);
+           Copy(tmpbuf, d, tculen, U8);
+           SvCUR_set(dest, need - 1);
        }
     }
     else {
-       U8 *s1;
-       if (!SvPADTMP(sv) || SvREADONLY(sv)) {
-           dTARGET;
-           SvUTF8_off(TARG);                           /* decontaminate */
-           sv_setsv_nomg(TARG, sv);
-           sv = TARG;
-           SETs(sv);
-       }
-       s1 = (U8*)SvPV_force_nomg(sv, slen);
-       if (*s1) {
+       if (*s) {
            if (IN_LOCALE_RUNTIME) {
                TAINT;
-               SvTAINTED_on(sv);
-               *s1 = (op_type == OP_UCFIRST)
-                   ? toUPPER_LC(*s1) : toLOWER_LC(*s1);
+               SvTAINTED_on(dest);
+               *d = (op_type == OP_UCFIRST)
+                   ? toUPPER_LC(*s) : toLOWER_LC(*s);
            }
            else
-               *s1 = (op_type == OP_UCFIRST) ? toUPPER(*s1) : toLOWER(*s1);
+               *d = (op_type == OP_UCFIRST) ? toUPPER(*s) : toLOWER(*s);
+       } else {
+           /* See bug #39028  */
+           *d = *s;
+       }
+
+       if (SvUTF8(source))
+           SvUTF8_on(dest);
+
+       if (!inplace) {
+           /* This will copy the trailing NUL  */
+           Copy(s + 1, d + 1, slen, U8);
+           SvCUR_set(dest, need - 1);
        }
     }
-    SvSETMAGIC(sv);
+    SvSETMAGIC(dest);
     RETURN;
 }
 

diff --git a/t/uni/overload.t b/t/uni/overload.t
index 407d4c6..38328f1 100644 (file)
--- a/t/uni/overload.t
+++ b/t/uni/overload.t
@@ -7,7 +7,7 @@ BEGIN {
     }
 }
 
-use Test::More tests => 16;
+use Test::More tests => 24;
 
 package UTF8Toggle;
 use strict;
@@ -72,5 +72,21 @@ SKIP: {
        $uc = uc $u;
        is (length $uc, 1);
        is ($uc, "\311", "e accute -> E accute");
+
+       $u = UTF8Toggle->new("\311");
+       $lc = lcfirst $u;
+       is (length $lc, 1);
+       is ($lc, "\351", "E accute -> e accute");
+       $lc = lcfirst $u;
+       is (length $lc, 1);
+       is ($lc, "\351", "E accute -> e accute");
+
+       $u = UTF8Toggle->new("\351");
+       $uc = ucfirst $u;
+       is (length $uc, 1);
+       is ($uc, "\311", "e accute -> E accute");
+       $uc = ucfirst $u;
+       is (length $uc, 1);
+       is ($uc, "\311", "e accute -> E accute");
     }
 }