RFR: JDK-8175795 configure should verify that system zlib contains needed functionality

[Magnus Ihse Bursie]

On 2017-12-04 12:14, Magnus Ihse Bursie wrote:
> I retract this review for now. The issue turned out to be not so 
> simple as this. We *are* able to build with older versions of zlib. 
> The dependency for inflateValidate arises from the bundled libpng; a 
> system libpng does not necessary have that issue.
Actually, the bundled libpng makes a version check for zlib... So it 
*should* work even with older zlibs. Probably the reporter of the bug 
had run into an issue with a zlib clone like zlib-ng, e.g. 
https://github.com/Dead2/zlib-ng/issues/80.

Normally, I don't think it's worth adding checks to configure for every 
possible broken package there is out there. But since someone actually 
ran into this (and I've already written most of the patch), here's an 
updated version:

http://cr.openjdk.java.net/~ihse/JDK-8175795-check-for-system-zlib-functionality/webrev.02

/Magnus

>
> /Magnus
>
> On 2017-12-04 11:57, Magnus Ihse Bursie wrote:
>> If we're using the system zlib instead of the bundled zlib, we should 
>> verify that it includes all relevant functions. We now rely on the 
>> inflateValidate() function, which was introduced in zlib 1.2.9 which 
>> is very recent. This patch adds a test to the system zlib to verify 
>> this and to fail fast in case it's too old.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8175795
>> WebRev: 
>> http://cr.openjdk.java.net/~ihse/JDK-8175795-check-for-system-zlib-functionality/webrev.01
>>
>> /Magnus
>>
>