As described in the linked issue, NullClassBytesTest fails due an OutOfMemoryError produced on AIX when the test calls defineClass with a byte array of size of 0. The native implementation of defineClass then calls malloc with a size of 0. On AIX malloc(0) returns NULL, while on other platforms it return a valid address. When NULL is produced by malloc for this reason, ClassLoader.c incorrectly interprets this as a failure due to a lack of memory.
This PR modifies ClassLoader.c to produce an OutOfMemoryError only when `errno == ENOMEM` and to produce a ClassFormatError with the message "ClassLoader internal allocation failure" in all other cases (in which malloc returns NULL). In addition, I performed some minor tidy-up work in ClassLoader.c by changing instances of `return 0` to `return NULL`, and `if (some_ptr == 0)` to `if (some_ptr == NULL)`. This was done to improve the clarity of the code in ClassLoader.c, but didn't feel worthy of opening a separate issue. ### Alternatives It would be possible to address this failure by modifying the test to accept the OutOfMemoryError on AIX. I thought it was a better solution to modify ClassLoader.c to produce an OutOfMemoryError only when the system is actually out of memory. ### Testing This change has been tested on AIX and Linux/x86. ------------- Commit messages: - Extract memory error logic to helper procedure - Updates copyright year and adds bug-id to test - Addresses NullClassBytesTest Failure Changes: https://git.openjdk.java.net/jdk/pull/7829/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7829&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8283225 Stats: 43 lines in 2 files changed: 20 ins; 0 del; 23 mod Patch: https://git.openjdk.java.net/jdk/pull/7829.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/7829/head:pull/7829 PR: https://git.openjdk.java.net/jdk/pull/7829
