LUCENE-5777: fix double escaping of dash in hunspell conditions

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1603851 13f79535-47bb-0310-9956-ffa450edef68

lucene/CHANGES.txt

@@ -343,7 +343,7 @@ Bug fixes
 * LUCENE-5747: Project-specific settings for the eclipse development
   environment will prevent automatic code reformatting. (Shawn Heisey)
 
-* LUCENE-5768: Hunspell condition checks containing character classes
+* LUCENE-5768, LUCENE-5777: Hunspell condition checks containing character classes
   were buggy. (Clinton Gormley, Robert Muir)
 
 Test Framework

lucene/analysis/common/src/java/org/apache/lucene/analysis/hunspell/Dictionary.java

@@ -356,6 +356,25 @@ public class Dictionary {
     }
     return builder.finish();
   }
+  
+  static String escapeDash(String re) {
+    // we have to be careful, even though dash doesn't have a special meaning,
+    // some dictionaries already escape it (e.g. pt_PT), so we don't want to nullify it
+    StringBuilder escaped = new StringBuilder();
+    for (int i = 0; i < re.length(); i++) {
+      char c = re.charAt(i);
+      if (c == '-') {
+        escaped.append("\\-");
+      } else {
+        escaped.append(c);
+        if (c == '\\' && i + 1 < re.length()) {
+          escaped.append(re.charAt(i+1));
+          i++;
+        }
+      }
+    }
+    return escaped.toString();
+  }
 
   /**
    * Parses a specific affix rule putting the result into the provided affix map
@@ -425,7 +444,7 @@ public class Dictionary {
       }
       // "dash hasn't got special meaning" (we must escape it)
       if (condition.indexOf('-') >= 0) {
-        condition = condition.replace("-", "\\-");
+        condition = escapeDash(condition);
       }
 
       final String regex;

lucene/analysis/common/src/test/org/apache/lucene/analysis/hunspell/TestDoubleEscape.java

@@ -0,0 +1,31 @@
+package org.apache.lucene.analysis.hunspell;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import org.junit.BeforeClass;
+
+public class TestDoubleEscape extends StemmerTestBase {
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    init("double-escaped.aff", "double-escaped.dic");
+  }
+  
+  public void testStemming() {
+    assertStemsTo("adubo", "adubar");
+  }
+}

lucene/analysis/common/src/test/org/apache/lucene/analysis/hunspell/double-escaped.aff

@@ -0,0 +1,5 @@
+SET UTF-8
+
+SFX X Y 1
+SFX X   ar         o          [^\-]ar
+

lucene/analysis/common/src/test/org/apache/lucene/analysis/hunspell/double-escaped.dic

@@ -0,0 +1,2 @@
+1
+adubar/X