FIX: FIND/TAIL not working properly with CHAR as an argument to search

(regression from previous FIND/MATCH changes)

Author: Oldes

src/core/s-find.c

@@ -523,8 +523,10 @@
 		c1 = GET_ANY_CHAR(ser, index);
 		if (uncase && c1 < UNICODE_CASES) c1 = LO_CASE(c1);
 
-		if (c1 == c2) return index;
-
+		if (c1 == c2) {
+			if GET_FLAG(flags, ARG_FIND_TAIL - 1) index++;
+			return index;
+		}
 		if GET_FLAG(flags, ARG_FIND_MATCH-1) break;
 	}
 

src/tests/units/series-test.r3

@@ -67,6 +67,17 @@ Rebol [
 ;	--assert none? find/part "abcd" "bc" 2
 ;	--assert none? find/part/any "abcd" "*c" 2
 
+--test-- "FIND char in string"
+	str: "a,b"
+	--assert ",b" = find str #","
+	--assert ",b" = find/reverse tail str #","
+	--assert "b"  = find/tail str #","
+	--assert "b"  = find/tail/reverse tail str #","
+	--assert "b"  = find str #"b"
+	--assert "b"  = find str #"B"
+	--assert "b"  = find/case str #"b"
+	--assert none?  find/case str #"B"
+
 --test-- https://github.com/rebol/rebol-issues/issues/66
 	--assert none? find/skip [1 2 3 4 5 6] 2 3