Ensure the origin of all variables inherited from the environment is
"environment override" if -e is given. Previously only variables
that were set in the makefile had this origin.
PDS: Most of these changes are from Dmitry but I slightly modified
the algorithm: instead of rearranging the way in which MAKEFLAGS is
parsed we reset the env_override value to the default before we
re-parse MAKEFLAGS, then we set the origin of all env vars to the
correct value based on the new setting.
* NEWS: Mention the change for backward-compatibility.
* src/main.c (main): Ensure MAKEFLAGS is always marked special.
(reset_makeflags): Set env_overrides back to default before parsing
MAKEFLAGS.
(decode_switches): Call reset_env_override() to check for changes.
* src/variable.h (reset_env_override): Declare a new function.
* src/variable.c (reset_env_override): Go through all env variables
and ensure the origin is correct based on env_overrides.
(set_env_override): Helper function for the hash.
* tests/scripts/functions/foreach: Fix tests.
* tests/scripts/functions/let: Ditto.
* tests/scripts/functions/origin: Ditto.
* tests/scripts/options/dash-e: Add tests.
* tests/test_driver.pl: Preserve the LSAN_OPTIONS variable.
* tests/scripts/targets/ONESHELL: Don't set a local variable.
* tests/scripts/functions/let: Test empty let variable.
* src/posixos.c (osync_parse_mutex): Free existing osync_tmpfile.
* src/misc.c (get_tmpfd): Set umask() before invoking mkstemp().
* src/ar.c (ar_parse_name): Check invalid name (shouldn't happen).
* src/function.c (define_new_function): Free previous function entry
when replacing it with a new one.
* src/job.c (child_execute_job): Initialize pid for safety.
(construct_command_argv_internal): In oneshell mode ensure that the
returned argv has the right format (0th element is a pointer to the
entire buffer).
Add a new function $(let ...) which allows lexically scoped variables.
* NEWS: Add information on this feature.
* doc/make.texi (Let Function): Document the 'let' function.
* src/function.c (func_let): Create the 'let' built-in function.
* tests/scripts/functions/let: Test the 'let' built-in function.
