4 files changed, 43 insertions, 8 deletions

diff --git a/op.c b/op.c
index 2ea2ef8ef7..a0c4f3587f 100644
--- a/op.c
+++ b/op.c
@@ -3432,14 +3432,24 @@ Perl_pmruntime(pTHX_ OP *o, OP *expr, bool isreg)
     pm = (PMOP*)o;
 
     if (expr->op_type == OP_CONST) {
-	SV * const pat = ((SVOP*)expr)->op_sv;
+	SV *pat = ((SVOP*)expr)->op_sv;
 	U32 pm_flags = pm->op_pmflags & PMf_COMPILETIME;
 
 	if (o->op_flags & OPf_SPECIAL)
 	    pm_flags |= RXf_SPLIT;
 
-	if (DO_UTF8(pat))
-	    pm_flags |= RXf_UTF8;
+	if (DO_UTF8(pat)) {
+	    assert (SvUTF8(pat));
+	} else if (SvUTF8(pat)) {
+	    /* Not doing UTF-8, despite what the SV says. Is this only if we're
+	       trapped in use 'bytes'?  */
+	    /* Make a copy of the octet sequence, but without the flag on, as
+	       the compiler now honours the SvUTF8 flag on pat.  */
+	    STRLEN len;
+	    const char *const p = SvPV(pat, len);
+	    pat = newSVpvn_flags(p, len, SVs_TEMP);
+	}
+	assert(!(pm_flags & RXf_UTF8));
 
 	PM_SETRE(pm, CALLREGCOMP(pat, pm_flags));
 
diff --git a/pp_ctl.c b/pp_ctl.c
index 6353df6a40..d2094f538f 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -148,8 +148,18 @@ PP(pp_regcomp)
 	    if (PL_op->op_flags & OPf_SPECIAL)
 		PL_reginterp_cnt = I32_MAX; /* Mark as safe.  */
 
-	    if (DO_UTF8(tmpstr))
-		pm_flags |= RXf_UTF8;
+	    if (DO_UTF8(tmpstr)) {
+		assert (SvUTF8(tmpstr));
+	    } else if (SvUTF8(tmpstr)) {
+		/* Not doing UTF-8, despite what the SV says. Is this only if
+		   we're trapped in use 'bytes'?  */
+		/* Make a copy of the octet sequence, but without the flag on,
+		   as the compiler now honours the SvUTF8 flag on tmpstr.  */
+		STRLEN len;
+		const char *const p = SvPV(tmpstr, len);
+		tmpstr = newSVpvn_flags(p, len, SVs_TEMP);
+	    }
+	    assert(!(pm_flags & RXf_UTF8));
 
  		if (eng) 
 	        PM_SETRE(pm, CALLREGCOMP_ENG(eng, tmpstr, pm_flags));
diff --git a/regcomp.c b/regcomp.c
index b71e54620c..a7b1cf6fdb 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -4151,7 +4151,7 @@ Perl_pregcomp(pTHX_ const SV * const pattern, const U32 flags)
 #endif
 
 REGEXP *
-Perl_re_compile(pTHX_ const SV * const pattern, const U32 pm_flags)
+Perl_re_compile(pTHX_ const SV * const pattern, U32 pm_flags)
 {
     dVAR;
     REGEXP *rx;
@@ -4175,7 +4175,10 @@ Perl_re_compile(pTHX_ const SV * const pattern, const U32 pm_flags)
     GET_RE_DEBUG_FLAGS_DECL;
     DEBUG_r(if (!PL_colorset) reginitcolors());
 
-    RExC_utf8 = RExC_orig_utf8 = pm_flags & RXf_UTF8;
+    RExC_utf8 = RExC_orig_utf8 = SvUTF8(pattern);
+    assert(!(pm_flags & RXf_UTF8));
+    if (RExC_utf8)
+	pm_flags |= RXf_UTF8;
 
     DEBUG_COMPILE_r({
         SV *dsv= sv_newmortal();
diff --git a/regexec.c b/regexec.c
index 95bba2e270..8144f998f7 100644
--- a/regexec.c
+++ b/regexec.c
@@ -3755,7 +3755,19 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
 			U32 pm_flags = 0;
 			const I32 osize = PL_regsize;
 
-			if (DO_UTF8(ret)) pm_flags |= RXf_UTF8;
+			if (DO_UTF8(ret)) {
+			    assert (SvUTF8(ret));
+			} else if (SvUTF8(ret)) {
+			    /* Not doing UTF-8, despite what the SV says. Is
+			       this only if we're trapped in use 'bytes'?  */
+			    /* Make a copy of the octet sequence, but without
+			       the flag on, as the compiler now honours the
+			       SvUTF8 flag on ret.  */
+			    STRLEN len;
+			    const char *const p = SvPV(ret, len);
+			    ret = newSVpvn_flags(p, len, SVs_TEMP);
+			}
+			assert(!(pm_flags & RXf_UTF8));
 			rx = CALLREGCOMP(ret, pm_flags);
 			if (!(SvFLAGS(ret)
 			      & (SVs_TEMP | SVs_PADTMP | SVf_READONLY