Trigger causes WEB BASED leads to be rejected?

Question

Is there a resource somewhere that would help me figure out why a trigger I wrote is causing web-based leads to be rejected? I get an email containing each lead when this trigger is running. Or, can someone simply TELL me what is wrong here? "Unexpected exception" isn't very helpful (see below). :-/

This trigger searches for duplicate leads (or accounts if the code is uncommented) and marks how many it found into a couple of fields - essentially a dupe checker (based on email address which is how this company operates) so we can filter them as needed - non-dupes go through, dupes get manhandled.

The code works FINE (though this version is several revisions later) except for rejecting web-based lead insertions from web-forms.

Thanks for any guidance. ;-) Code is below.

trigger emailDuplicateCounter_LEAD on Lead (before insert) {
//trigger emailDuplicateCounter_LEAD on Lead (before insert, before update) {

// ORIGINAL...
// http://www.salesforce.com/docs/developer/cookbook/Content/apex_dedupe.htm

    Map<String, Lead> leadMap = new Map<String, Lead>([select id, Email from Lead WHERE Name != '' ]);

// Reset Dupe Email (leads) marker; add email(s) to list of those to check
    for (Lead leadLoop : System.Trigger.new) { 
//  ins 1 + 2
        leadMap.put(leadLoop.Email, leadLoop);
    }

// Single dbase query, find all leads with same email address as any of the leads being ins 
    for ( Lead leadLoop2 : [SELECT Email FROM Lead WHERE Email IN :leadMap.KeySet()] ) {
        Lead newLead = leadMap.get(leadLoop2.Email);
//  ins 3
        if (System.Trigger.isInsert) { 
            newLead.Dupe_Email_in_leads_When_Created__c = true; 
        }
    }

// check Accounts similarly...         ** COMMENTED FOR NOW **
//    for ( Account account : [SELECT PersonEmail FROM Account WHERE PersonEmail IN :leadMap.KeySet()] ) {
//        Lead newLead = leadMap.get(account.PersonEmail);
//  ins 4
//        if (System.Trigger.isInsert) { 
            //newLead.Dupe_Email_in_accounts_When_Created__c = true; 
//        }
    }

// code to fix/ insert later with more logic...
// 1     leadLoop.Dupe_Email_in_leads__c = false;
// 2     leadLoop.Dupe_Email_in_Accounts__c = false;
// 3     newLead.Dupe_Email_in_leads__c = true;    would need on UPDATE, misfires....
// 4     newLead.Dupe_Email_in_accounts__c = true;   similar to above...

}

The error on the emails that contain the non-inserted lead is:

Salesforce could not create this lead because of the reason listed below. For more information about this error or help with Web-to-Case-Lead, please contact Customer Support.

Reason: Apex trigger emailDuplicateCounter_LEAD caused an unexpected exception, contact your administrator: emailDuplicateCounter_LEAD: execution of BeforeInsert

caused by: System.NullPointerException: Attempt to de-reference a null object: Trigger.emailDuplicateCounter_LEAD

Answer 1

Whenever we try to get from Map we usually put a null check to avoid null pointer exceptions

For example

for ( Account account : [SELECT PersonEmail FROM Account WHERE PersonEmail  IN:leadMap.KeySet()] ) {
  //        Lead newLead = leadMap.get(account.PersonEmail);

Modified like this for ( Account account : [SELECT PersonEmail FROM Account WHERE PersonEmail IN:leadMap.KeySet()] ) {

      if(leadMap.get(account.PersonEmail)!=null){//Avoid null pointer exception
      //        Lead newLead = leadMap.get(account.PersonEmail);

Looks like we will have to put null checks and should solve the issue .Say if some value is null in any of fields null pointer exception will come