From 75a07d0a2245a3f97c7d741dce05faaebcdb2f7a Mon Sep 17 00:00:00 2001
From: Andy Stadler <>
Date: Tue, 24 Mar 2009 21:33:34 -0700
Subject: [PATCH] Automated import from //branches/master/...@142111,142111

---
 .../james/mime4j/decoder/DecoderUtil.java     | 15 +++++-
 .../email/mail/internet/MimeUtilityTest.java  | 46 ++++++++++++++++++-
 2 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/src/org/apache/james/mime4j/decoder/DecoderUtil.java b/src/org/apache/james/mime4j/decoder/DecoderUtil.java
index f7b9fa8f8..7876ff700 100644
--- a/src/org/apache/james/mime4j/decoder/DecoderUtil.java
+++ b/src/org/apache/james/mime4j/decoder/DecoderUtil.java
@@ -166,7 +166,20 @@ public class DecoderUtil {
 
         while (true) {
             int begin = body.indexOf("=?", previousEnd);
-            int end = begin == -1 ? -1 : body.indexOf("?=", begin + 2);
+            
+            // ANDROID:  The mime4j original version has an error here.  It gets confused if
+            // the encoded string begins with an '=' (just after "?Q?").  This patch seeks forward
+            // to find the two '?' in the "header", before looking for the final "?=".
+            int endScan = begin + 2;
+            if (begin != -1) {
+                int qm1 = body.indexOf('?', endScan + 2);
+                int qm2 = body.indexOf('?', qm1 + 1);
+                if (qm2 != -1) {
+                    endScan = qm2 + 1;
+                }
+            }
+            
+            int end = begin == -1 ? -1 : body.indexOf("?=", endScan);
             if (end == -1) {
                 if (previousEnd == 0)
                     return body;
diff --git a/tests/src/com/android/email/mail/internet/MimeUtilityTest.java b/tests/src/com/android/email/mail/internet/MimeUtilityTest.java
index b39e4cf0d..814774b3c 100644
--- a/tests/src/com/android/email/mail/internet/MimeUtilityTest.java
+++ b/tests/src/com/android/email/mail/internet/MimeUtilityTest.java
@@ -48,6 +48,31 @@ public class MimeUtilityTest extends TestCase {
     /** a typical multi-param header */
     private final String HEADER_MULTI_PARAMETER = 
             "header; Param1Name=Param1Value; Param2Name=Param2Value";
+    
+    /**
+     * a string generated by google calendar that contains two interesting gotchas:
+     * 1.  Uses windows-1252 encoding, and en-dash recoded appropriately (\u2013 / =96)
+     * 2.  Because the first encoded char requires '=XX' encoding, we create an "internal"
+     *     "?=" that the decoder must correctly skip over.
+     **/
+    private final String CALENDAR_SUBJECT_UNICODE = 
+        "=?windows-1252?Q?=5BReminder=5D_test_=40_Fri_Mar_20_10=3A30am_=96_11am_=28andro?=" +
+        "\r\n\t" +
+        "=?windows-1252?Q?id=2Etr=40gmail=2Ecom=29?=";
+    private final String CALENDAR_SUBJECT_PLAIN =
+        "[Reminder] test @ Fri Mar 20 10:30am \u2013 11am (android.tr@gmail.com)";
+    
+    /**
+     * Some basic degenerate strings designed to exercise error handling in the decoder
+     */
+    private final String CALENDAR_DEGENERATE_UNICODE_1 =
+        "=?windows-1252?Q=5B?=";
+    private final String CALENDAR_DEGENERATE_UNICODE_2 =
+        "=?windows-1252Q?=5B?=";
+    private final String CALENDAR_DEGENERATE_UNICODE_3 =
+        "=?windows-1252?=";
+    private final String CALENDAR_DEGENERATE_UNICODE_4 =
+        "=?windows-1252";
 
     /**
      * Test that decode/unfold is efficient when it can be
@@ -82,7 +107,26 @@ public class MimeUtilityTest extends TestCase {
         assertEquals(SHORT_UNICODE, result1);
     }
     
-    // TODO:  tests for unfoldAndDecode(String s)
+    /**
+     * test decoding complex string from google calendar that has two gotchas for the decoder.
+     * also tests a couple of degenerate cases that should "fail" decoding and pass through.
+     */
+    public void testComplexDecode() {
+        String result1 = MimeUtility.unfoldAndDecode(CALENDAR_SUBJECT_UNICODE);
+        assertEquals(CALENDAR_SUBJECT_PLAIN, result1);
+        
+        // These degenerate cases should "fail" and return the same string
+        String degenerate1 = MimeUtility.unfoldAndDecode(CALENDAR_DEGENERATE_UNICODE_1);
+        assertEquals("degenerate case 1", CALENDAR_DEGENERATE_UNICODE_1, degenerate1);
+        String degenerate2 = MimeUtility.unfoldAndDecode(CALENDAR_DEGENERATE_UNICODE_2);
+        assertEquals("degenerate case 2", CALENDAR_DEGENERATE_UNICODE_2, degenerate2);
+        String degenerate3 = MimeUtility.unfoldAndDecode(CALENDAR_DEGENERATE_UNICODE_3);
+        assertEquals("degenerate case 3", CALENDAR_DEGENERATE_UNICODE_3, degenerate3);
+        String degenerate4 = MimeUtility.unfoldAndDecode(CALENDAR_DEGENERATE_UNICODE_4);
+        assertEquals("degenerate case 4", CALENDAR_DEGENERATE_UNICODE_4, degenerate4);
+    }
+    
+    // TODO:  more tests for unfoldAndDecode(String s)
 
     /**
      * Test that fold/encode is efficient when it can be