extensions that depend on other extensions (such as record) use this pattern
to check if the dependant extension is available:
try:
mq = extensions.find('mq')
except KeyError:
return
but since if an error occurs while loading an extension it leaves its entry
in the _extensions map as None, we want to raise in that situation too.
(rather than adding another check if the return value is None)
Example
$ hg clone --jump foo bar
hg clone: option --jump not recognized
hg clone [OPTION]... SOURCE [DEST]
make a copy of an existing repository
options:
-U --noupdate the clone will include an empty working copy (only a
repository)
-u --updaterev REV revision, tag or branch to check out
-r --rev REV [+] include the specified changeset
-b --branch BRANCH [+] clone only the specified branch
--pull use pull protocol to copy metadata
--uncompressed use uncompressed transfer (fast over LAN)
-e --ssh CMD specify ssh command to use
--remotecmd CMD specify hg command to run on the remote side
--insecure do not verify server certificate (ignoring
web.cacerts config)
[+] marked option can be specified multiple times
use "hg help clone" to show the full help text
Motivation for this change
If the user already has specified the command, he probably already knows
the command to some extent. Apparently, he has a problem with the options,
so we show him just the synopsis with the short help and the details about
the options, with a hint on the last line how to get the full help text.
Why is Mercurial better with this change?
Experts who just forgot about the details of an option don't get that
much text thrown at them, while the newbies still get a hint on the last
line how to get the full help text.
This turns the prompt sequence from something like:
$ examine changes to foo?
$ record change 1/4 to foo?
$ record change 2/4 to foo?
$ examine changes to bar?
$ record change 4/4 to bar?
into:
$ examine changes to foo?
$ record change 1/3 to foo?
$ record change 2/3 to foo?
$ examine change to bar?
$ record change 3/3 to bar?
203ffed27f86 made this simple test-test.t succeed silently:
$ printf ' $ true' > test-test.t
but did not give a usable .err in this case:
$ printf ' $ false' > test-test.t
The missing LF will now be fixed in the test output and it will thus give a
test failure and a solution in the .err file.
