RFR: 8282628: Potential memory leak in sun.font.FontConfigManager.getFontConfig()

[David Holmes]

On Tue, 8 Mar 2022 09:18:01 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

>> Please review this small patch that fixes a potential memory leak that exception return fails to release allocated `cacheDirs`
>> 
>> Test:
>> 
>> - [x] jdk_desktop on Linux x86_64
>
> src/java.desktop/unix/native/common/awt/fontpath.c line 938:
> 
>> 936:             while ((cnt < max) && (cacheDir = (*FcStrListNext)(cacheDirs))) {
>> 937:                 jstr = (*env)->NewStringUTF(env, (const char*)cacheDir);
>> 938:                 JNU_CHECK_EXCEPTION_AND_CLEANUP(env, (*FcStrListDone)(cacheDirs));
> 
> I think you do not need to create an additional macro here, just inline it and call "(*FcStrListDone)(cacheDirs);" directly. Something like:
> 
> if (IS_NULL(jstr) {
>     (*FcStrListDone)(cacheDirs);
>     return;
> }
> 
> Note that the "IS_NULL" is used in this file after NewStringUTF. Any objections?

Good catch! Elsewhere in this file IS_NULL is always used to check NewStringUTF, so the existing code was inconsistent in checking for a pending exception.

Checking for NULL and checking for a pending exception are logically equivalent as long as the passed in pointer is not NULL.

-------------

PR: https://git.openjdk.java.net/jdk/pull/7691