RFR(XS): 8244495: Some jlink tests crash on Windows after JDK-8237750

[David Holmes]

Hi Yumin,

On 7/05/2020 11:01 am, Yumin Qi wrote:
> Hi,
>    Please review the fix for
>    bug: https://bugs.openjdk.java.net/browse/JDK-8244495
>    webrev: http://cr.openjdk.java.net/~minqi/8244495/webrev/
> 
> Tests tools/jlink/JLinkTest.javaand tools/jlink/basic/BasicTest.java 
> failed after 8237750 pushed. The fix of 8237750 changed default behavior 
> of loading zip library to on-demand loading. jlink (and jimage) assumes 
> that zip library was loaded already, so call to FindEntry caused 
> ACCESS_VIOLATION on Windows. This is a Windows specific problem. 
> GetModuleHandle is used on the library already loaded and won't load the 
> library if it's not loaded.

Fix looks good.

I was wondering why we crashed when the method already potentially 
returns NULL but I see:

  88         ZipInflateFully = (ZipInflateFully_t) 
findEntry("ZIP_InflateFully");
   89      assert(ZipInflateFully != NULL && "ZIP decompressor not found.");

so in product builds we assume it is non-NULL and try to call it. And 
unfortunately IIUC JDK tier2 tests only run on product builds - hence 
why we never saw a simple and obvious assertion failure in the CI.

Thanks,
David
-----

>     Tests: tier1-2 passed.
> 
>    Thanks
>    Yumin