fix for bug #20401. prevent user from creating two identical

mailnews accounts.
(identical means they have the same {username,hostname,type}.)
r=mscott

mailnews/base/prefs/resources/content/AccountWizard.js

@@ -222,7 +222,6 @@ function AccountDataToPageData(accountData, pageData)
     }
 }
 
-
 // take data from each page of pageData and dump it into accountData
 // use: to put results of wizard into a account-oriented object
 function PageDataToAccountData(pageData, accountData)
@@ -566,6 +565,28 @@ function serverIsNntp(pageData) {
     return false;
 }
 
+function getUsernameFromEmail(email)
+{
+	var emailData = email.split("@");
+    return emailData[0];
+}
+
+function getCurrentUserName(pageData)
+{
+	var userName = "";
+
+	if (pageData.login) {
+    	if (pageData.login.username) {
+        	userName = pageData.login.username.value;
+		}
+	}
+	if (userName == "") {
+		var email = pageData.identity.email.value;
+		userName = getUsernameFromEmail(email); 
+	}
+	return userName;
+}
+
 function getCurrentServerType(pageData) {
     var servertype = "pop3";    // hopefully don't resort to default!
     if (serverIsNntp(pageData))
@@ -642,7 +663,6 @@ function PrefillAccountForIsp(ispName)
     AccountDataToPageData(ispData, pageData);
 }
 
-
 // does any cleanup work for the the account data
 // - sets the username from the email address if it's not already set
 // - anything else?
@@ -652,8 +672,7 @@ function FixupAccountDataForIsp(accountData)
     var username;
 
     if (email) {
-        var emailData = email.split("@");
-        username = emailData[0];
+		username = getUsernameFromEmail(email);
     }
     
     // fix up the username

mailnews/base/prefs/resources/content/aw-server.js

@@ -34,6 +34,30 @@ function validate() {
     window.alert(alertText);
     return false;
   }
+
+  dump("check if this account exists\n");
+  var pageData = parent.GetPageData();
+  var hostName = servername.value;
+  var serverType = parent.getCurrentServerType(pageData);
+  var userName = parent.getCurrentUserName(pageData);
+
+  var accountExists = false;
+  var accountManager = Components.classes["component://netscape/messenger/account-manager"].getService(Components.interfaces.nsIMsgAccountManager);
+  try {
+	var server = accountManager.FindServer(userName,hostName,serverType);
+	if (server) {
+		accountExists = true;
+	}
+  }
+  catch (ex) {
+	accountExists = false;
+  }
+  if (accountExists) {
+    var alertText = Bundle.GetStringFromName("accountExists");
+    window.alert(alertText);
+    return false;
+  }
+
   return true;
 }
 

mailnews/base/prefs/resources/locale/en-US/prefs.properties

@@ -27,6 +27,7 @@ enterAccountName=Please enter a name for this account.
 enterUserName=Please enter a username.
 enterName=Please enter your name.
 enterValidEmail=Please enter a valid email address.
+accountExists=An account of this type with the same username and hostname already exists.  Go back and change it or hit cancel.
 
 # when the wizard already has a domain (Should we say something different?)
 enterValidEmailPrefix=Please enter a valid email address.