From a31f9affde680d1b93b1283955764d247ee3bb4d Mon Sep 17 00:00:00 2001 From: Volodymyr Chernetskyi Date: Mon, 7 Sep 2026 14:24:16 +0200 Subject: fix(msgpack): strptime() fails east of UTC+12 #41743 Problem: msgpack#strptime() finds a timestamp by bisecting strftime() output, and brackets the search with the extreme UTC offsets. The lower bound subtracts 12 hours, but -12:00 is the westernmost offset, which produces the *largest* timestamp for a given local time. The easternmost offset is +14:00, so in any zone east of UTC+12 the search can start above the target and the function throws: internal-start-string:Internal error: start > string With TZ=GMT-14, four of the five timestamps in msgpack_spec.lua fail, as do three tests in shada_spec.lua, which reaches the same function through shada#strings_to_sd(). Solution: Subtract 14 hours instead. The upper bound is already generous enough at +14, and widening a bisection bracket downwards cannot change the result in zones that worked before. The test disables the python3 provider, because msgpack#strptime() only uses the Vimscript implementation changed here when no provider answers, and otherwise hands the work to datetime.strptime(). AI-assisted --- test/functional/plugin/msgpack_spec.lua | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'test/functional/plugin/msgpack_spec.lua') diff --git a/test/functional/plugin/msgpack_spec.lua b/test/functional/plugin/msgpack_spec.lua index a2255a3855..6e9467e159 100644 --- a/test/functional/plugin/msgpack_spec.lua +++ b/test/functional/plugin/msgpack_spec.lua @@ -735,3 +735,25 @@ describe('autoload/msgpack.vim', function() end) end) end) + +describe('autoload/msgpack.vim in an eastern timezone', function() + setup(function() + clear({ + -- msgpack#strptime() prefers a Python implementation and only falls back to the + -- Vimscript one, which is the one under test, when no provider answers. + args = { '-u', 'NORC', '--cmd', 'let g:loaded_python3_provider = 0' }, + -- POSIX TZ signs are inverted: GMT-14 is UTC+14, the easternmost offset. + env = { TZ = 'GMT-14' }, + }) + end) + + describe('function msgpack#strptime', function() + it('works east of UTC+12 #7625', function() + eq(0, nvim_eval('has("python3")')) + for _, v in ipairs({ 0, 10, 100000, 204, 1000000000 }) do + local time = nvim_eval(('strftime("%%Y-%%m-%%dT%%H:%%M:%%S", %d)'):format(v)) + eq(v, nvim_eval(('msgpack#strptime("%%Y-%%m-%%dT%%H:%%M:%%S", "%s")'):format(time))) + end + end) + end) +end) -- cgit