Quit utf8_to_uv() instantly if curlen == 0.

p4raw-id: //depot/perl@7693

diff --git a/utf8.c b/utf8.c
index 5d0fdc6..3cee2c2 100644 (file)
--- a/utf8.c
+++ b/utf8.c
@@ -195,6 +195,13 @@ Perl_utf8_to_uv(pTHX_ U8* s, STRLEN curlen, STRLEN* retlen, U32 flags)
     bool dowarn = ckWARN_d(WARN_UTF8);
     STRLEN expectlen = 0;
     
+    if (curlen == 0) {
+       if (dowarn)
+           Perl_warner(aTHX_ WARN_UTF8,
+                       "Malformed UTF-8 character (an empty string)");
+       goto malformed;
+    }
+
     if (uv <= 0x7f) { /* Pure ASCII. */
        if (retlen)
            *retlen = 1;
@@ -210,7 +217,7 @@ Perl_utf8_to_uv(pTHX_ U8* s, STRLEN curlen, STRLEN* retlen, U32 flags)
        goto malformed;
     }
 
-    if ((uv >= 0xc0 && uv <= 0xfd && curlen >1 && s[1] < 0x80) &&
+    if ((uv >= 0xc0 && uv <= 0xfd && curlen > 1 && s[1] < 0x80) &&
        !(flags & UTF8_ALLOW_NON_CONTINUATION)) {
        if (dowarn)
            Perl_warner(aTHX_ WARN_UTF8,
@@ -246,7 +253,7 @@ Perl_utf8_to_uv(pTHX_ U8* s, STRLEN curlen, STRLEN* retlen, U32 flags)
        if (dowarn)
            Perl_warner(aTHX_ WARN_UTF8,
                        "Malformed UTF-8 character (%d byte%s, need %d)",
-                       curlen, curlen > 1 ? "s" : "", expectlen);
+                       curlen, curlen == 1 ? "" : "s", expectlen);
        goto malformed;
     }
 
@@ -302,7 +309,7 @@ Perl_utf8_to_uv(pTHX_ U8* s, STRLEN curlen, STRLEN* retlen, U32 flags)
        if (dowarn)
            Perl_warner(aTHX_ WARN_UTF8,
                        "Malformed UTF-8 character (%d byte%s, need %d)",
-                       expectlen, expectlen > 1 ? "s": "", UNISKIP(uv));
+                       expectlen, expectlen == 1 ? "": "s", UNISKIP(uv));
        goto malformed;
     }