Yuya pointed out that using mutable value as the default could be problematic.
To work around this we now support callable object as default value. This
allows for creating new mutable objects on demand when needed.
If the option is registered, there is already a default value available and
passing a new one is at best redundant. So we issue a deprecation warning in
this case.
(note: there will be case were the default value will not be as simple as what
is currently possible. We'll upgrade the configitems code to handle them in
time.)
We do not have any registered config yet, but we are now ready to use them.
For now we ignore this feature for config access with "alternates". On the long
run, we expect alternates to be handled as "aliases" by the config item
themself.
This should let 'configdate' delegate all special processing of the default
config value to the main 'config' method.
The default value for date (None) is still enforced in this method if no other
default were passed.
This should let 'configlist' delegate all special processing of the default
config value to the main 'config' method.
The default config value ([]) is still handled in this method.
This should let 'configwith' delegate all special processing of the default
config value to the main 'config' method.
This changeset introduce a small change in behavior since the default value is
run through the 'convert' function. This does not seems harmful and no actual
test break. This small change make the code simpler so I'm keeping it.
This should let 'configbool' delegate all special processing of the default
config value to the main 'config' method.
The default value for bool (False) is still enforced in this method if no other
default were passed.
We introduce a small object used to detect that no specific default value has
been passed to 'ui.config'. We need this explicit special value since "None" is
a valid and common default value.
The end goal here is to make progress on a centralised and explicit declaration
of the available config option. A first good usecase for this are "default"
value. Before starting looking further down this alley we needs to rework the
handling of default value in the 'ui' object to have all configxyz methods going
through the same logic. This is the first changeset on this trek.
We've been talking for years about a one-stop config knob to opt in to
better behavior. There have been a lot of ideas thrown around, but
they all seem to be too complicated to get anyone to actually do the
work.. As such, this patch is the stupidest thing that can possibly
work in the name of getting a good feature to users.
Right now it's just three config settings that I think are generally
uncontroversial, but I expect to add more soon. That will likely
include adding new config knobs for the express purpose of adding them
to tweakdefaults.
d46a7814be5f refactored util.parsedate in order to raise ValueError instead
of Abort for using with ui.configwith. It causes several problems, putting
arbitrary bytes in ValueError can cause issues with Python 3. Moreover, we
added a function to convert ValueError exceptions back to Abort.
A better approach would be to make parsedate raises ParseError, removing
the convert function and update configwith to also catch ParseError.
The side-effect is that error message when giving an invalid date in CLI
change from:
abort: invalid date: 'foo bar'
to:
hg: parse error: invalid date: 'foo bar'
I'm not sure if it's an acceptable change, I found personally the error
message more clear but more verbose too.
d46a7814be5f introduced util._parsedate with the aim to be used in
ui.configdate but ui.configdate was using util.parsedate instead. It have the
impact of raising an AbortError in case of an invalid date instead of a
ConfigError exception. Fix ui.configdate to use the right function and add a
test for invalid dates.
Thanks to Yuya for the catch!
This option was never released except for a release candidate. Dropping
compatibility with this option will free the 'pager.enable' config option for
other usage in the future.
This aligns with what we do for color (see cea7a760c58d). Pager is a central
enough notion that having the master config in the [ui] section makes senses. It
will helps with consistency, discoverability. It will also help having a simple
and clear example hgrc mentioning pager.
The previous form of the option had never been released in a non-rc version but
we keep it around for convenience. If both are set, 'ui.pager' take priority.
"Churn" is not the useful example we have, but this is the one used in
'hg help config.extensions'. As we need something to replace the deprecated
'pager' extension in the example config, we are adding 'churn'.
The prior code used to ignore all errors, which was intended to
deal with a decade-old problem with writing to broken pipes on
Windows.
However, that code inadvertantly went a lot further, making it
impossible to detect *all* I/O errors on stdio ... but only sometimes.
What actually happened was that if Mercurial wrote less than a stdio
buffer's worth of output (the overwhelmingly common case for most
commands), any error that occurred would get swallowed here. But
if the buffering strategy changed, an unhandled IOError could be
raised from any number of other locations.
Because we now have a top-level StdioError handler, and ui._write
and ui._write_err (and now flush!) will raise that exception, we
have one rational place to detect and handle these errors.
In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:
* Handlers run after application code has finished.
* Because of this, the code that runs handlers swallows exceptions
(since there's no possible stacktrace to associate errors with).
If we're lucky, we'll get something spat out to stderr (if stderr
still works), which of course isn't any use in a big deployment
where it's important that exceptions get logged and aggregated.
* Mercurial's current atexit handlers make unfortunate assumptions
about process state (specifically stdio) that, coupled with the
above problems, make it impossible to deal with certain categories
of error (try "hg status > /dev/full" on a Linux box).
* In Python 3, the atexit implementation is completely hidden, so
we can't hijack the platform's atexit code to run handlers at a
time of our choosing.
As a result, here's a perfectly cromulent atexit-like implementation
over which we have control. This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).
Text IO sucks on Python 3 as it must be a unicode stream. We could introduce
a wrapper that converts unicode back to bytes, but it wouldn't be simple to
handle offsets transparently from/to underlying IOBase API.
Fortunately, we don't need to process huge text files, so let's stick to
bytes IO and convert EOL in memory.
When --pager=on is given, dispatch.py spawns a pager before setting up color.
If the pager failed to launch, ui.pageractive was left set to True, so color
configured itself based on 'color.pagermode'. A typical MSYS setting would be
'color.mode=auto, color.pagermode=ansi'. In the failure case, this would print
a warning, disable the pager, and then print the raw ANSI codes to the terminal.
Care needs to be taken, because it appears that leaving ui.pageractive=True was
the only thing that prevented an attempt at running the pager again from inside
the command. This results in a double warning message, so pager is simply
disabled on failure.
The ui config settings didn't need to be moved to fix this, but it seemed like
the right thing to do for consistency.
The next patches will convert environ to raw config items, and insert the
config items between systemrcpath and userrcpath. This patch teaches
rccomponents to return the type information so the caller could distinguish
between "path" and raw config "items".
As discussed at [1], the logic around "actual config"s seem to be
non-trivial enough that it's worth a new module.
This patch creates the module and move "scmutil.*rcpath" functions there as
the first step. More methods will be moved to the module in the future.
The module is different from config.py because the latter only cares about
data structure and parsing, and does not care about special case, or system
config paths, or environment variables.
[1]: https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-March/095503.html
Hardcoding 'more' -> 'more.com' means that 'more.exe' from MSYS would need to be
configured with its *.exe extension. This will resolve to either one, as
cmd.exe would have done if the command ran through the shell.
Something that's maybe problematic with this is it comes after 'pageractive' and
various ui configs have been set by the calling method. But the other early
exits in this method don't undo those changes either.
After 6a86fe38f1f6, with 'shell' being (mostly) set to False, invoking `more` no
longer worked. Instead, a warning was printed and the pager was disabled.
Invoking `more.com` works. Since a user may have configured 'pager.pager=more',
do this substitution at the end. Surprisingly, `more` does allow for arguments,
so those are preserved. This also allows `more` to work in MSYS.
Setting 'shell=False' runs the executable via CreateProcess(), which has rather
wonky rules for resolving an executable without an extension [1]. Resolving to
*.com is not among them. Since 'shell=True' yields a cryptic error for a bad
$PAGER, and a *.exe program will work without specifying the extension, sticking
with current 'shell=False' seems like the right thing to do. I don't think
there are any other *.com pagers out there, so this one special case seems OK.
If somebody wants to do something crazy that requires cmd.exe, I was able to get
normal paged output with 'pager.pager="cmd.exe /c more"'. I assume you can
replace `more` with *.bat, *.vbs or various other creatures listed in $PATHEXT.
[1] https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx
