Updating many rows with the same CLOB or BLOB values could result in FileNotFoundException.

h2/src/main/org/h2/result/RowList.java

@@ -70,7 +70,12 @@ public class RowList {
                     if (lobs == null) {
                         lobs = ObjectArray.newInstance();
                     }
+                    // need to create a copy, otherwise,
+                    // if stored multiple times, it may be renamed
+                    // and then not found
+                    lob = lob.copyToTemp();
                     lobs.add(lob);
+                    v = lob;
                 }
             }
             buff.checkCapacity(buff.getValueLen(v));

h2/src/main/org/h2/value/ValueLob.java

@@ -838,4 +838,20 @@ public class ValueLob extends Value {
         return 128;
     }
 
+    /**
+     * Create an independent copy of this temporary value.
+     * The file will not be deleted automatically.
+     *
+     * @return the value
+     */
+    public ValueLob copyToTemp() throws SQLException {
+        ValueLob lob;
+        if (type == CLOB) {
+            lob = ValueLob.createClob(getReader(), precision, handler);
+        } else {
+            lob = ValueLob.createBlob(getInputStream(), precision, handler);
+        }
+        return lob;
+    }
+
 }

h2/src/test/org/h2/test/db/TestLob.java

@@ -23,7 +23,6 @@ import java.sql.Savepoint;
 import java.sql.Statement;
 import java.util.ArrayList;
 import java.util.Random;
-
 import org.h2.constant.SysProperties;
 import org.h2.store.FileLister;
 import org.h2.test.TestBase;
@@ -49,6 +48,7 @@ public class TestLob extends TestBase {
         if (config.memory) {
             return;
         }
+        testLobUpdateMany();
         testLobDeleteTemp();
         testLobDelete();
         testLobVariable();
@@ -73,6 +73,17 @@ public class TestLob extends TestBase {
         deleteDb("lob");
     }
 
+    private void testLobUpdateMany() throws SQLException {
+        deleteDb("lob");
+        Connection conn = getConnection("lob");
+        Statement stat = conn.createStatement();
+        stat.execute("create table post(id int primary key, text clob) as select x, space(96) from system_range(1, 329)");
+        PreparedStatement prep = conn.prepareStatement("update post set text = ?");
+        prep.setCharacterStream(1, new StringReader(new String(new char[1025])), -1);
+        prep.executeUpdate();
+        conn.close();
+    }
+
     private void testLobDeleteTemp() throws SQLException {
         deleteDb("lob");
         Connection conn = getConnection("lob");