Removes 32-bit limit on substr arguments. The full range of IV and UV is available for the pos and len arguments, with safe conversion to STRLEN where it's smaller than an IV.

1 files changed, 9 insertions, 10 deletions

diff --git a/mg.c b/mg.c
index b9a1464938..4f8207c1af 100644
--- a/mg.c
+++ b/mg.c
@@ -2008,17 +2008,17 @@ Perl_magic_getsubstr(pTHX_ SV *sv, MAGIC *mg)
     STRLEN len;
     SV * const lsv = LvTARG(sv);
     const char * const tmps = SvPV_const(lsv,len);
-    I32 offs = LvTARGOFF(sv);
-    I32 rem = LvTARGLEN(sv);
+    STRLEN offs = LvTARGOFF(sv);
+    STRLEN rem = LvTARGLEN(sv);
 
     PERL_ARGS_ASSERT_MAGIC_GETSUBSTR;
     PERL_UNUSED_ARG(mg);
 
     if (SvUTF8(lsv))
-	sv_pos_u2b(lsv, &offs, &rem);
-    if (offs > (I32)len)
+	sv_pos_u2b_proper(lsv, &offs, &rem);
+    if (offs > len)
 	offs = len;
-    if (rem + offs > (I32)len)
+    if (rem > len - offs)
 	rem = len - offs;
     sv_setpvn(sv, tmps + offs, (STRLEN)rem);
     if (SvUTF8(lsv))
@@ -2033,22 +2033,22 @@ Perl_magic_setsubstr(pTHX_ SV *sv, MAGIC *mg)
     STRLEN len;
     const char * const tmps = SvPV_const(sv, len);
     SV * const lsv = LvTARG(sv);
-    I32 lvoff = LvTARGOFF(sv);
-    I32 lvlen = LvTARGLEN(sv);
+    STRLEN lvoff = LvTARGOFF(sv);
+    STRLEN lvlen = LvTARGLEN(sv);
 
     PERL_ARGS_ASSERT_MAGIC_SETSUBSTR;
     PERL_UNUSED_ARG(mg);
 
     if (DO_UTF8(sv)) {
 	sv_utf8_upgrade(lsv);
- 	sv_pos_u2b(lsv, &lvoff, &lvlen);
+	sv_pos_u2b_proper(lsv, &lvoff, &lvlen);
 	sv_insert(lsv, lvoff, lvlen, tmps, len);
 	LvTARGLEN(sv) = sv_len_utf8(sv);
 	SvUTF8_on(lsv);
     }
     else if (lsv && SvUTF8(lsv)) {
 	const char *utf8;
-	sv_pos_u2b(lsv, &lvoff, &lvlen);
+	sv_pos_u2b_proper(lsv, &lvoff, &lvlen);
 	LvTARGLEN(sv) = len;
 	utf8 = (char*)bytes_to_utf8((U8*)tmps, &len);
 	sv_insert(lsv, lvoff, lvlen, utf8, len);
@@ -2059,7 +2059,6 @@ Perl_magic_setsubstr(pTHX_ SV *sv, MAGIC *mg)
 	LvTARGLEN(sv) = len;
     }
 
-
     return 0;
 }