foldEQ_utf8(): Move rare tests out of main stream

The code for handling locale can be moved entirely to the place where
locale handling is done for the second string, as by that time we have
processed the first string, and the second.  Since we only succeed
if both are atomic, single-bytes, we don't need to do the loop below.

1 files changed, 12 insertions, 14 deletions

diff --git a/utf8.c b/utf8.c
index d496afce75..9d3770d78f 100644
--- a/utf8.c
+++ b/utf8.c
@@ -3195,6 +3195,8 @@ Perl_foldEQ_utf8_flags(pTHX_ const char *s1, char **pe1, register UV l1, bool u1
 	    if ((flags & FOLDEQ_UTF8_LOCALE)
 		&& (! u2 || UTF8_IS_INVARIANT(*p2) || UTF8_IS_DOWNGRADEABLE_START(*p2)))
 	    {
+		/* Here, the next char in s2 is < 256.  We've already worked on
+		 * s1, and if it isn't also < 256, can't match */
 		if (u1 && (! UTF8_IS_INVARIANT(*p1)
 		    && ! UTF8_IS_DOWNGRADEABLE_START(*p1)))
 		{
@@ -3206,7 +3208,13 @@ Perl_foldEQ_utf8_flags(pTHX_ const char *s1, char **pe1, register UV l1, bool u1
 		else {
 		    *foldbuf2 = TWO_BYTE_UTF8_TO_UNI(*p2, *(p2 + 1));
 		}
-		n2 = 1;
+
+		/* Use another function to handle locale rules.  We've made
+		 * sure that both characters to compare are single bytes */
+		if (! foldEQ_locale((char *) f1, (char *) foldbuf2, 1)) {
+		    return 0;
+		}
+		n1 = n2 = 0;
 	    }
 	    else if (isASCII(*p2)) {
 		if (flags && ! isASCII(*p1)) {
@@ -3225,19 +3233,9 @@ Perl_foldEQ_utf8_flags(pTHX_ const char *s1, char **pe1, register UV l1, bool u1
             f2 = foldbuf2;
         }
 
-	/* Here f1 and f2 point to the beginning of the strings to compare.  In
-	 * the case of Unicode rules, these strings are the folds of the input
-	 * characters, stored in utf8.  In the case of locale rules, they are
-	 * the original characters, each stored as a single byte. */
-
-	/* Use another function to handle locale rules.  n1 has to equal n2
-	 * under them, as they've been converted to single bytes above */
-	if (flags & FOLDEQ_UTF8_LOCALE && n1 == 1) {
-	    if (! foldEQ_locale((char *) f1, (char *) f2, 1)) {
-		return 0;
-	    }
-	    n1 = n2 = 0;
-	}
+	/* Here f1 and f2 point to the beginning of the strings to compare.
+	 * These strings are the folds of the input characters, stored in utf8.
+	 */
 
         /* While there is more to look for in both folds, see if they
         * continue to match */