BUG #21036, myOperation->getBlobHandle(..) on non-existing column cause segmentation fault

add judgement to avoid NULL pointer's operation(segmentaion fault)

ndb/src/ndbapi/NdbOperation.cpp

@@ -319,13 +319,31 @@ NdbOperation::setValue( Uint32 anAttrId,
 NdbBlob*
 NdbOperation::getBlobHandle(const char* anAttrName)
 {
-  return getBlobHandle(theNdbCon, m_currentTable->getColumn(anAttrName));
+  const NdbColumnImpl* col = m_currentTable->getColumn(anAttrName);
+  if (col == NULL)
+  {
+    setErrorCode(4004);
+    return NULL;
+  }
+  else
+  {
+    return getBlobHandle(theNdbCon, col);
+  }
 }
 
 NdbBlob*
 NdbOperation::getBlobHandle(Uint32 anAttrId)
 {
-  return getBlobHandle(theNdbCon, m_currentTable->getColumn(anAttrId));
+  const NdbColumnImpl* col = m_currentTable->getColumn(anAttrId);
+  if (col == NULL)
+  {
+    setErrorCode(4004);
+    return NULL;
+  }
+  else
+  {
+    return getBlobHandle(theNdbCon, col);
+  }
 }
 
 int

ndb/src/ndbapi/ndberror.c

@@ -401,7 +401,7 @@ ErrorBundle ErrorCodes[] = {
    * Still uncategorized
    */
   { 720,  AE, "Attribute name reused in table definition" },
-  { 4004, AE, "Attribute name not found in the Table" },
+  { 4004, AE, "Attribute name or id not found in the table" },
   
   { 4100, AE, "Status Error in NDB" },
   { 4101, AE, "No connections to NDB available and connect failed" },