[OpenJDK 2D-Dev] [12] JDK-8212202: NPE in the print tests after JDK-8153732

Shashidhara Veerabhadraiah shashidhara.veerabhadraiah at oracle.com
Tue Nov 27 06:23:42 UTC 2018


The windows function EnumPrinters() returns a value that could be zero or greater. If it is zero we have no other option but to return null from the function. I do not think there is a way where we can always make sure we get a non-zero value considering the various system scenarios. So we should handle the null return values as well in the caller of this function I think.

 

Here is the updated Webrev for test fix:

http://cr.openjdk.java.net/~sveerabhadra/8212202/webrev.01/

 

Thanks and regards,
Shashi

 

From: Phil Race 
Sent: Tuesday, November 27, 2018 1:52 AM
To: Prasanta Sadhukhan <prasanta.sadhukhan at oracle.com>; Shashidhara Veerabhadraiah <shashidhara.veerabhadraiah at oracle.com>; 2d-dev at openjdk.java.net
Subject: Re: [OpenJDK 2D-Dev] [12] JDK-8212202: NPE in the print tests after JDK-8153732

 

[Removed swing-dev as this as nothing to do with swing].

You mention in the bug eval that you don't need a new test because this
is already covered by the test for 8153732. If that is the case then this
bugid should be added to that test.
Although it also looks like there are plenty of tests that provoke this ..
if all you need is a system without any printers then this is a serious regression.

I am not sure I am following why doCompare() is the place to fix this.
If getRemotePrinterNames() is returning NULL strings, then maybe it should not !

I suggest to fix it there.

-phil.




On 11/26/18 7:51 AM, Prasanta Sadhukhan wrote:

I am not against doCompare() changes. I am just saying run() changes are not needed.

Regards
Prasanta

On 26-Nov-18 9:15 PM, Shashidhara Veerabhadraiah wrote:

There is a possible case and that is the reason for this fix. The possible states for prevRemotePinters and currentRemotePrinters are null and valid values and they can reach those states at any time either because of network disconnect or any other OS related changes. With that in mind, this fix tries to eliminate the possible NPE cases.

 

Thanks and regards,

Shashi

 

From: Prasanta Sadhukhan 
Sent: Monday, November 26, 2018 8:01 PM
To: Shashidhara Veerabhadraiah HYPERLINK "mailto:shashidhara.veerabhadraiah at oracle.com"<shashidhara.veerabhadraiah at oracle.com>; HYPERLINK "mailto:swing-dev at openjdk.java.net"swing-dev at openjdk.java.net; HYPERLINK "mailto:2d-dev at openjdk.java.net"2d-dev at openjdk.java.net
Subject: Re: [OpenJDK 2D-Dev] [12] JDK-8212202: NPE in the print tests after JDK-8153732

 

 

 

On 26-Nov-18 6:51 PM, HYPERLINK "mailto:shashidhara.veerabhadraiah at oracle.com"shashidhara.veerabhadraiah at oracle.com wrote:

Hi Prasanta, I think we should not create a behavior across the functions. doCompare() does only the comparison and it may be used for other purposes and is complete with respect to the comparison functionality.

run() function has a different behavior as it needs to populate the prevRemotePrinters and then the currentRemotePrinters and then use the comparison functionality. I think this is a good way to do.

Even without the if-else check, it does populates the prevRemotePrinters, no? 
if "prevRemotePrinters" is null and currentRemotePrinters is null, then no need to update. If currentRemotePrinters is null, then what is the point of using getRemotePrintersNames() to update prevRemotePrinters as currentRemotePrinters is also obtained from getRemotePrintersNames!!
If "prevRemotePrinters" is null and currentRemotePrinters is not null, then doCompare() called from run() will be true and prevRemotePrinters will be populated with currentRemotePrinters.
If "prevRemotePrinters" is not null and currentRemotePrinters is null, then also prevRemotePrinters will be populated with currentRemotePrinters.

Regards
Prasanta




Thanks and regards,

Shashi

 

On 26/11/18 6:03 PM, Prasanta Sadhukhan wrote:

Hi Shashi,

I think l437 check of if-else if (prevRemotePrinters != null) {

 

is not required. prevRemotePrinters null check is addressed in str1==null case in doCompare().
If prevRemotePrinters is null and currentRemotePrinters is not null, then you update prevRemotePrinters to currentRemotePrinters as per l415 where doCompare returns true.
Also, If prevRemotePrinters is not null and currentRemotePrinters is null, then also you update prevRemotePrinters to currentRemotePrinters which is the output of getRemotePrintersNames().

Regards
Prasanta




On 26-Nov-18 2:33 PM, Shashidhara Veerabhadraiah wrote:

Hi All, Please review a NPE fix for the below bug.

 

Bug: https://bugs.openjdk.java.net/browse/JDK-8212202

 

Webrev: HYPERLINK "http://cr.openjdk.java.net/%7Esveerabhadra/8212202/webrev.00/"http://cr.openjdk.java.net/~sveerabhadra/8212202/webrev.00/

 

Function getRemotePrintersNames() may return null values and hence they need to be handled from the caller of that function which was missing earlier. This fix handles the null return values of the said function.

 

Thanks and regards,

Shashi

 

 

 

 

 
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