index: remove side-effect from failed nt_init() As pointed out by Yuya in the review of D4108, if we run into the "overflow in nt_init" case (which I think normally happens only in repos with at least 2^26=64Mi revisions), we would leave the node tree half-initialized. Differential Revision: https://phab.mercurial-scm.org/D4153

index: use PyMem_Free() to free nodeetree instance As Yuya pointed out in the review of D4108, PyMem_Malloc() and PyMem_Free() should be paired. IIUC, PyMem_Malloc() may use a different allocator than malloc(), so using free() with a pointer from PyMem_Malloc() may be very wrong. Differential Revision: https://phab.mercurial-scm.org/D4152

linelog: fix infinite loop vulnerability Checking `len(lines)` is not a great way of detecting infinite loops, as demonstrated in the added test. Therefore check instruction count instead. The original C implementation does not have this problem. There are a few other places where the C implementation enforces more strictly, like `a1 <= a2`, `b1 <= b2`, `rev > 0`. But they are optional. Test Plan: Add a test. The old code forces the test to time out. Differential Revision: https://phab.mercurial-scm.org/D4151

tests: fix bytes/str issues in run-tests.py caught by python3 Differential Revision: https://phab.mercurial-scm.org/D4143