revlog: don't say "not found" on internal error If index_node() returned NULL, then index_find_node() and and nt_partialmatch() used to return -2 to signal that the node was not found. However, we were passing in a revnum to index_node() that we knew should exist, so the only reason it could return NULL was due to some internal error or perhaps out of memory. Let's not use "not found" for these cases. I suppose we never noticed this because these error never happen in practice. I think there are more places where we should error out instead of reporting that the node was not found, but the cases mentioned above were all I cared about right now (because using the same error code for all failures simplified some future patches). Differential Revision: https://phab.mercurial-scm.org/D3457

revlog: extract function for getting node from known-to-exist rev Many of the calls to index_node() (which converts a rev to a nodeid) are done with a rev that's know to exist. If the function fails, there's something really wrong and we should just abort. This was done in only one place. This patch starts by extracting that code to a function that we can reuse in later patches. Differential Revision: https://phab.mercurial-scm.org/D3456

shortest: make {shortest("fffffffff")} work again {shortest("fffffffff")} should shorten it to the shortest unambiguous prefix for the working directory. It used to do that until I broke it in 7b2955624777 (scmutil: make shortesthexnodeidprefix() take a full binary nodeid, 2018-04-14), when we started returning the full hex nodeid for any working directory prefix shorter than 40 hex digits. This patch fixes it by catching WdirUnsupported specifically. Differential Revision: https://phab.mercurial-scm.org/D3455

revlog: use radix tree also for matching keys shorter than 4 hex digits I don't know what the reason for the 4-digit limit was, and I can't think of any real disadvantages of using the radix tree also when the requested minimum length is short. This speeds up `hg log -T '{shortest(node,1)}\n'` from 2m16s to 4.5s by making that not fall back to pure code. Differential Revision: https://phab.mercurial-scm.org/D3453

context: convert to hex for error message only for 20-byte changeid Now that 20-byte strings unambiguously mean binary (or a bug), we can specialize the conversion to hex for that case. Differential Revision: https://phab.mercurial-scm.org/D3452

context: clarify that only one attempt is made to interpret changeid We can now tell what type of revision specifier we have just by looking at it (we no longer attempt to interpret it in one way after the other -- that's now in scmutil.revsymbol()). Let's clarify this in the code by swithing to if/elif. Differential Revision: https://phab.mercurial-scm.org/D3451

context: only bother looking for broken dirstate for 20-byte changeid If we fail to look up a changeid in changectx.__init__, we check if it exactly matches any of the dirstate parents, and if it does, we print a more specific message ("working directory has unknown parent '...'!" instead of "unknown revision '...'"). The dirstate parents are always 20 bytes, so there's no need to check for a match when the given changeid is not 20 bytes. (And now that all the other allowed forms of changeid have been moved out of the constructor, there's no risk that a changeid that did match a dirstate parent was actually a valid bookmark.) Differential Revision: https://phab.mercurial-scm.org/D3450