MVStore: improved detection of the wrong encryption key (or file corruption)

h2/src/main/org/h2/mvstore/DataUtils.java

@@ -592,6 +592,11 @@ public class DataUtils {
                     while (i < size) {
                         c = s.charAt(i++);
                         if (c == '\\') {
+                            if (i == size) {
+                                throw DataUtils.newIllegalStateException(
+                                        DataUtils.ERROR_FILE_CORRUPT,
+                                        "Not a map: {0}", s);
+                            }
                             c = s.charAt(i++);
                         } else if (c == '\"') {
                             break;

h2/src/test/org/h2/test/store/TestDataUtils.java

@@ -10,6 +10,8 @@ import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.Random;
+
 import org.h2.mvstore.DataUtils;
 import org.h2.test.TestBase;
 
@@ -32,6 +34,7 @@ public class TestDataUtils extends TestBase {
         testEncodeLength();
         testFletcher();
         testMap();
+        testMapRandomized();
         testMaxShortVarIntVarLong();
         testVarIntVarLong();
         testCheckValue();
@@ -79,6 +82,24 @@ public class TestDataUtils extends TestBase {
         assertEquals("\"test\"", m.get("d"));
     }
         
+    private void testMapRandomized() {
+        Random r = new Random(1);
+        String chars = "a_1,\\\":";
+        for (int i = 0; i < 1000; i++) {
+            StringBuilder buff = new StringBuilder();
+            for (int j = 0; j < 20; j++) {
+                buff.append(chars.charAt(r.nextInt(chars.length())));
+            }
+            try {
+                HashMap<String, String> map = DataUtils.parseMap(buff.toString());
+                assertFalse(map == null);
+                // ok
+            } catch (IllegalStateException e) {
+                // ok - but not another exception
+            }
+        }
+    }
+
     private void testMaxShortVarIntVarLong() {
         ByteBuffer buff = ByteBuffer.allocate(100);
         DataUtils.writeVarInt(buff, DataUtils.COMPRESSED_VAR_INT_MAX);