tests: avoid test-hup hanging on AIX test-hup hangs on AIX. Under ksh89 on AIX (the default shell), echo Hello; while [ ! -s not-there ]; do true; done produces no output while the loop executes. Replacing 'true' with 'sleep 0' fixes, as does using a less broken shell. ksh93 is fine. Update check-code.py to look for this, and make same change in test-serve.t. In fact test-serve works fine, probably because of additional commands between echo and the loop, but that's a subtlety not easy to test for.

parsers: incrementally parse the revlog index in C We only parse entries in a revlog index file when they are actually needed, and cache them when first requested. This makes a huge difference to performance on large revlogs when accessing the tip revision or performing a handful of numeric lookups (very common cases). For instance, "hg --time tip --template {node}" on a tree with 300,000 revs takes 0.15 before, 0.02 after. Even for revlog-intensive operations (e.g. running "hg log" to completion), the lazy approach is about 1% faster than the eager parse_index2.