Commit f9b6b37c authored by Committed by Damien GeorgeBrowse files
py: Fix wrong assumption that m_renew will not move if shrinking
In both parse.c and qstr.c, an internal chunking allocator tidies up by calling m_renew to shrink an allocated chunk to the size used, and assumes that the chunk will not move. However, when MICROPY_ENABLE_GC is false, m_renew calls the system realloc, which does not guarantee this behaviour. Environments where realloc may return a different pointer include: (1) mbed-os with MBED_HEAP_STATS_ENABLED (which adds a wrapper around malloc & friends; this is where I was hit by the bug); (2) valgrind on linux (how I diagnosed it). The fix is to call m_renew_maybe with allow_move=false.