Don't test already-referenced pointer for nullness
authorAlvaro Herrera <alvherre@alvh.no-ip.org>
Tue, 16 Jan 2024 11:27:52 +0000 (12:27 +0100)
committerAlvaro Herrera <alvherre@alvh.no-ip.org>
Tue, 16 Jan 2024 11:27:52 +0000 (12:27 +0100)
commitc6605c1bdf07e8fc026bf857d37628cbb5746bb8
tree7a98d2efd87c7647a49ffb232841aff6394ef88a
parenta37bb7c13995b834095d9d064cad1023a6f99b10
Don't test already-referenced pointer for nullness

Commit b8ba7344e9eb added in PQgetResult a derefence to a pointer
returned by pqPrepareAsyncResult(), before some other code that was
already testing that pointer for nullness.  But since commit
618c16707a6d (in Postgres 15), pqPrepareAsyncResult() doesn't ever
return NULL (a statically-allocated result is returned if OOM).  So in
branches 15 and up, we can remove the redundant pointer check with no
harm done.

However, in branch 14, pqPrepareAsyncResult() can indeed return NULL if
it runs out of memory.  Fix things there by adding a null pointer check
before dereferencing the pointer.  This should hint Coverity that the
preexisting check is not redundant but necessary.

Backpatch to 14, like b8ba7344e9eb.

Per Coverity.
src/interfaces/libpq/fe-exec.c