Change core to use is_invariant_string()

is_ascii_string's name has misled me in the past; the new name is
clearer.

1 files changed, 9 insertions, 8 deletions

diff --git a/mg.c b/mg.c
index 653800347a..27c276249a 100644
--- a/mg.c
+++ b/mg.c
@@ -751,15 +751,16 @@ S_fixup_errno_string(pTHX_ SV* sv)
          * case we should turn on that flag.  This didn't use to happen, and to
          * avoid as many possible backward compatibility issues as possible, we
          * don't turn on the flag unless we have to.  So the flag stays off for
-         * an entirely ASCII string.  We assume that if the string looks like
-         * UTF-8, it really is UTF-8:  "text in any other encoding that uses
-         * bytes with the high bit set is extremely unlikely to pass a UTF-8
-         * validity test" (http://en.wikipedia.org/wiki/Charset_detection).
-         * There is a potential that we will get it wrong however, especially
-         * on short error message text.  (If it turns out to be necessary, we
-         * could also keep track if the current LC_MESSAGES locale is UTF-8) */
+         * an entirely invariant string.  We assume that if the string looks
+         * like UTF-8, it really is UTF-8:  "text in any other encoding that
+         * uses bytes with the high bit set is extremely unlikely to pass a
+         * UTF-8 validity test"
+         * (http://en.wikipedia.org/wiki/Charset_detection).  There is a
+         * potential that we will get it wrong however, especially on short
+         * error message text.  (If it turns out to be necessary, we could also
+         * keep track if the current LC_MESSAGES locale is UTF-8) */
         if (! IN_BYTES  /* respect 'use bytes' */
-            && ! is_ascii_string((U8*) SvPVX_const(sv), SvCUR(sv))
+            && ! is_invariant_string((U8*) SvPVX_const(sv), SvCUR(sv))
             && is_utf8_string((U8*) SvPVX_const(sv), SvCUR(sv)))
         {
             SvUTF8_on(sv);