ICU-2874 fix parsing of [^-b]

X-SVN-Rev: 11871

icu4c/source/common/uniset.cpp

@@ -1963,6 +1963,12 @@ void UnicodeSet::_applyPattern(const UnicodeString& pattern,
                 isLiteral = TRUE; // Treat leading '-' as a literal
                 break; // Fall through
             }
+            break;
+        case 2:
+            if (c == HYPHEN && invert) {
+                isLiteral = TRUE; // [^-...] starts with literal '-'
+            }
+            break;
             // else fall through and parse this character normally
         }
 

icu4c/source/test/intltest/usettest.cpp

@@ -793,6 +793,23 @@ void UnicodeSetTest::TestPropertySet() {
         "[:xdigit:]",
         "09afAF",
         "gG!",
+
+        // Regex compatibility test
+        "[-b]", // leading '-' is literal
+        "-b",
+        "ac",
+
+        "[^-b]", // leading '-' is literal
+        "ac",
+        "-b",
+
+        "[b-]", // trailing '-' is literal
+        "-b",
+        "ac",
+
+        "[^b-]", // trailing '-' is literal
+        "ac",
+        "-b"
     };
 
     static const int32_t DATA_LEN = sizeof(DATA)/sizeof(DATA[0]);