Integrate mainline

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

diff --git a/util.c b/util.c
index a9f9ade..3a23678 100644 (file)
--- a/util.c
+++ b/util.c
@@ -4346,5 +4346,42 @@ Perl_sv_nounlocking(pTHX_ SV *sv)
 {
 }
 
+/*
+=for apidoc memcmp_byte_utf8
+
+Similar to memcmp(), but the first string is with bytes, the second
+with utf8.  Takes into account that the lengths may be different.
 
+=cut
+*/
 
+int
+Perl_memcmp_byte_utf8(pTHX_ char *sb, STRLEN lbyte, char *su, STRLEN lutf)
+{
+    U8 *sbyte = (U8*)sb;
+    U8 *sutf  = (U8*)su;
+    U8 *ebyte = sbyte + lbyte;
+    U8 *eutf  = sutf  + lutf;
+
+    while (sbyte < ebyte) {
+       if (sutf >= eutf)
+           return 1;                   /* utf one shorter */
+       if (NATIVE_IS_INVARIANT(*sbyte)) {
+           if (*sbyte != *sutf)
+               return *sbyte - *sutf;
+           sbyte++; sutf++;    /* CONTINUE */
+       } else if ((*sutf & UTF_CONTINUATION_MASK) ==
+                   (*sbyte >> UTF_ACCUMULATION_SHIFT)) {
+           if ((sutf[1] & UTF_CONTINUATION_MASK) !=
+                (*sbyte & UTF_CONTINUATION_MASK))
+               return (*sbyte & UTF_CONTINUATION_MASK) -
+                       (*sutf & UTF_CONTINUATION_MASK);
+           sbyte++, sutf += 2; /* CONTINUE */
+       } else
+           return (*sbyte >> UTF_ACCUMULATION_SHIFT) -
+                   (*sutf & UTF_CONTINUATION_MASK);
+    }
+    if (sutf >= eutf)
+       return 0;
+    return -1;                         /* byte one shorter */
+}