RFR(S): 8145015: jni_GetStringCritical asserts for empty strings

Volker Simonis volker.simonis at gmail.com
Wed Dec 9 17:53:29 UTC 2015


can somebody please review and sponsor the following fix:


The problem is that change "8141132: JEP 254: Compact Strings" removed
the handling for empty strings from jni_GetStringCritical(). As a
consequence, the functions will now assert with:

assert(is_within_bounds(which)) failed: index 0 out of bounds 0

if called with a string of length zero (because it tries to access the
zeroth element of a zero-length array).

The fix is trivial, just use 's_value->base(T_CHAR)' instead of

While doing this fix I also noticed that jni_GetStringCritical()
doesn't handle out-of-memory situations when creating a new character
array (before this wasn't necessary because it always returned the
original character array, but now with compressed strings it may have
to allocate a new array). So I've also added the new check by using

Notice that I also allocate one extra character for zero termination.
While it seems that this is not strictly necessary, it is now the same
code like in jni_GetStringChars(). And it again simplifies the
handling of zero-length strings. Without the extra character it would
be hard to distinguish out-of-memory errors from the allocation of
zero bytes, because malloc() is free to return NULL if called with an
allocation size of zero.

Thank you and best regards,

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