is_utf8_string

[p5sagit/p5-mst-13.2.git] / utf8.c

diff --git a/utf8.c b/utf8.c
index b570b12..666ec34 100644 (file)
--- a/utf8.c
+++ b/utf8.c
@@ -134,6 +134,30 @@ Perl_is_utf8_char(pTHX_ U8 *s)
     return len;
 }
 
+/*
+=for apidoc Am|bool_utf8_string|U8 *s|STRLEN len
+
+Returns true if first C<len> bytes of the given string form valid a UTF8
+string, false otherwise.
+
+=cut
+*/
+
+bool 
+Perl_is_utf8_string(pTHX_ U8 *s, STRLEN len)
+{
+    U8* x=s;
+    U8* send=s+len;
+    int c;
+    while (x < send) {
+        c = is_utf8_char(x);
+        x += c;
+        if (!c || x > send)
+            return 0;
+    }
+    return 1;
+}
+
 UV
 Perl_utf8_to_uv(pTHX_ U8* s, I32* retlen)
 {
@@ -223,10 +247,11 @@ Perl_utf8_hop(pTHX_ U8 *s, I32 off)
 }
 
 /*
-=for apidoc utf8_to_bytes
+=for apidoc Am|U8 *|utf8_to_bytes|U8 *s|STRLEN len
 
 Converts a string C<s> of length C<len> from UTF8 into ASCII encoding.
 Unlike C<bytes_to_utf8>, this over-writes the original string.
+Returns zero on failure after converting as much as possible.
 
 =cut
 */
@@ -247,6 +272,10 @@ Perl_utf8_to_bytes(pTHX_ U8* s, STRLEN len)
         else {
             I32 ulen;
             UV uv = utf8_to_uv(s, &ulen);
+            if (uv > 255) {
+                *d = '\0';
+                return 0;
+            }
             s += ulen;
             *d++ = (U8)uv;
         }
@@ -256,23 +285,25 @@ Perl_utf8_to_bytes(pTHX_ U8* s, STRLEN len)
 }
 
 /*
-=for apidoc bytes_to_utf8
+=for apidoc Am|U8 *|bytes_to_utf8|U8 *s|STRLEN *len
 
 Converts a string C<s> of length C<len> from ASCII into UTF8 encoding.
-Returns a pointer to the newly-created string.
+Returns a pointer to the newly-created string, and sets C<len> to
+reflect the new length.
 
+=cut
 */
 
 U8*
-Perl_bytes_to_utf8(pTHX_ U8* s, STRLEN len)
+Perl_bytes_to_utf8(pTHX_ U8* s, STRLEN *len)
 {
     dTHR;
     U8 *send;
     U8 *d;
     U8 *dst;
-    send = s + len;
+    send = s + (*len);
 
-    Newz(801, d, len * 2 + 1, U8);
+    Newz(801, d, (*len) * 2 + 1, U8);
     dst = d;
 
     while (s < send) {
@@ -285,6 +316,7 @@ Perl_bytes_to_utf8(pTHX_ U8* s, STRLEN len)
         }
     }
     *d = '\0';
+    *len = d-dst;
     return dst;
 }