patchbomb: use 'tiprev' when appropriate This is cleaner than the current 'len(repo) - 1' form.

revset: use 'tiprev' when appropriate This is cleaner than the current 'len(repo) - 1' forms

changelog: use 'tiprev()' in 'tip()' Since 'tip()' is just a node version of 'tiprev()' we should reuse the code.

changelog: introduce a 'tiprev' method Accessing tiprev is a common need through the code base. It is usually done using "len(changelog) -1". That form is tedious and error-prone. For example, it will give wrong results on filtered changelog (if the unfiltered tip is filtered). As a result, we introduce a simple 'tiprev()' method to provide this exact information in a nice way.

contrib: add some basic scaffolding for some fuzz test targets I'd like to get the majority of our C code covered by automated fuzz testing. I've started with bdiff because it was already decoupled from libpython and therefore was fairly quick to produce a working fuzzer. The code here is a little odd because I've been having trouble convincing libfuzzer to define a main and I threw in the towel. This code will also work with github.com/google/oss-fuzz, and once it lands in our main repo I intend to enable automated fuzzing in oss-fuzz with reports going to our security alias. Differential Revision: https://phab.mercurial-scm.org/D1875

formatting: enforce clang-format on all .cc files as well as .c files As part of my upcoming fuzzer patch we're going to grow some .cc files. They're not part of the release build (they're only used for fuzzing, which requires clang 6 which in turn implies a working C++ compiler), so I'm not terribly worried about growing some C++ files. Differential Revision: https://phab.mercurial-scm.org/D1874

hghave: add test for clang 6 and later clang 6 includes integrated libfuzzer support, which makes fuzzer stuff a little easier to work with. Differential Revision: https://phab.mercurial-scm.org/D1873

py3: cast error message to localstr in blackbox.py According to the exceptions reporting mechanism, this is the #1 crasher in the test harness for Python 3. Since this exception is in an except block, we'll likely get a new #1 crasher after this change. But at least we won't die during error handling! Differential Revision: https://phab.mercurial-scm.org/D1478

lfs: remove internal url in test `test-lfs-test-server.t` refers to a FB internal domain and requires certain implementation (ex. set error code to 404) at that endpoint. Without any workaround, It should in theory error out like "Domain cannot be resolved". I don't know how Matt Harbison ran the test. This patch changes the test to only depend on `lfs-test-server`. Unfortunately the logic has to be changed since `lfs-test-server` does not set error code to 404 but just removes "download" from "actions". Differential Revision: https://phab.mercurial-scm.org/D1849

lfs: control tracked file selection via a tracked file Since the lfs tracking policy can dramatically affect the repository, it makes more sense to have the policy file checked in, than to rely on all developers configuring their .hgrc properly. The inspiration for this is the .hgeol file. The configuration lives under '[track]', so that other things can be added in the future. Eventually, the config option should be limited to `convert` only. If the file can't be parsed for any reason (including unrecognized elements of the minifileset language), the commit will abort until the problem is corrected. This seems more useful than the warning that hgeol emits, and has no effect on reading the data, so there's no compatibility concerns. My initial thought was to read the file and change each "key = value" line into "((key) & (value))", so that each line could be ORed together, and make a single pass at compiling. Unfortunately, that prevents exclusions if there's a catchall rule. Consider what happens to a large *.c file here: [track] **.c = none() ** = size('>1MB') # ((**.c) & (none())) | ((**) & (size('>1MB'))) => anything > 1MB I also thought about having separate [include] and [exclude] sections. But that just seems to open things up to user mistakes. Consider: [include] **.zip = all() **.php = size('>10MB') [exclude] **.zip = all() # Who wins? **.php = none() # Effectively 'all()' (i.e. nothing excluded), or >10MB ? Therefore, it just compiles each key and value separately, and walks until the key matches something. I'm not sure how to enforce just file patterns on LHS without leaking knowledge about the minifileset here. That means this will allow odd looking lines like this: [track] **.c | **.txt = none() But that's also fewer lines to compile, so slightly more efficient? Some things like 'none()' won't work as expected on LHS though, because that won't match, so that line is skipped. For now, these quirks are not mentioned in the documentation. Jun previously expressed concern about efficiency when scaling to large repos, so I tried avoiding 'repo[None]'. (localrepo.commit() gets repo[None] already, but doesn't tie it to the workingcommitctx used here.) Therefore, I looked at the passed context for 'AMR' status. But that doesn't help with the normal case where the policy file is tracked, but clean. That requires looking up p1() to read the file. I don't see any way to get the content of one file without first creating the full parent context.