From e4ff7d9bb96ec8d840144288c801841ab4a78016 Mon Sep 17 00:00:00 2001
From: Sean Owen <srowen@gmail.com>
Date: Wed, 30 Jul 2014 12:18:04 +0100
Subject: [PATCH] Issue #197 : handle escaped backslash preceding terminator

---
 .../zxing/client/result/ResultParser.java     | 20 +++++++++++++++----
 .../result/WifiParsedResultTestCase.java      |  5 +++++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/com/google/zxing/client/result/ResultParser.java b/core/src/main/java/com/google/zxing/client/result/ResultParser.java
index 7cc1d4862..c86f1f7fc 100644
--- a/core/src/main/java/com/google/zxing/client/result/ResultParser.java
+++ b/core/src/main/java/com/google/zxing/client/result/ResultParser.java
@@ -116,7 +116,7 @@ public abstract class ResultParser {
   }
 
   protected static String unescapeBackslash(String escaped) {
-    int backslash = escaped.indexOf((int) '\\');
+    int backslash = escaped.indexOf('\\');
     if (backslash < 0) {
       return escaped;
     }
@@ -208,13 +208,13 @@ public abstract class ResultParser {
       int start = i; // Found the start of a match here
       boolean more = true;
       while (more) {
-        i = rawText.indexOf((int) endChar, i);
+        i = rawText.indexOf(endChar, i);
         if (i < 0) {
           // No terminating end character? uh, done. Set i such that loop terminates and break
           i = rawText.length();
           more = false;
-        } else if (rawText.charAt(i - 1) == '\\') {
-          // semicolon was escaped so continue
+        } else if (countPrecedingBackslashes(rawText, i) % 2 != 0) {
+          // semicolon was escaped (odd count of preceding backslashes) so continue
           i++;
         } else {
           // found a match
@@ -239,6 +239,18 @@ public abstract class ResultParser {
     return matches.toArray(new String[matches.size()]);
   }
 
+  private static int countPrecedingBackslashes(CharSequence s, int pos) {
+    int count = 0;
+    for (int i = pos - 1; i >= 0; i--) {
+      if (s.charAt(i) == '\\') {
+        count++;
+      } else {
+        break;
+      }
+    }
+    return count;
+  }
+
   static String matchSinglePrefixedField(String prefix, String rawText, char endChar, boolean trim) {
     String[] matches = matchPrefixedField(prefix, rawText, endChar, trim);
     return matches == null ? null : matches[0];
diff --git a/core/src/test/java/com/google/zxing/client/result/WifiParsedResultTestCase.java b/core/src/test/java/com/google/zxing/client/result/WifiParsedResultTestCase.java
index bfad97102..43fc2540f 100644
--- a/core/src/test/java/com/google/zxing/client/result/WifiParsedResultTestCase.java
+++ b/core/src/test/java/com/google/zxing/client/result/WifiParsedResultTestCase.java
@@ -64,6 +64,11 @@ public final class WifiParsedResultTestCase extends Assert {
     doTest("WIFI:S:TenChars;P:hello\\:there;T:WEP;;", "TenChars", "hello:there", "WEP");
   }
 
+  @Test
+  public void testEscape() {
+    doTest("WIFI:T:WPA;S:test;P:my_password\\\\;;", "test", "my_password\\", "WPA");
+  }
+
   /**
    * Given the string contents for the barcode, check that it matches our expectations
    */