putenv: handles a string starting with = as error

Change-Id: I1ff288080ac468b5f8a75f2064e68e8086dc7a69
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5539
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

Conform putenv to POSIX standards

Discovered this while working on VLC, checked with other online sources too.

Change-Id: I114c20babda0ff0e90d0eeee299d8483700166bd
Reviewed-on: https://review.haiku-os.org/c/1628
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

libroot_debug: Merge guarded heap into libroot_debug.

The individual debug heap implementations are now exposed via a
structure of function pointers and a common frontend dispatches the
malloc and malloc_debug APIs through them.

The MALLOC_DEBUG environment variable can be used to select the guarded
heap by adding 'g', otherwise the debug heap is used as the default.
Consequently the separate libroot_guarded is not needed anymore and has
been removed.

To allow the use of environment variables this early, init_env_post_heap
has been added and the heap dependent atfork() moved there. This allowed
to fold the code of init_heap_post_env into init_heap so the former has
been removed.

Add private __getenv_reentrant()

A reentrant variant of getenv().

Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version

unsetenv() should remove *any* occurence of name=value.
As with putenv() both value and name can be modified afterwise in our
back, multiple occurence of the same name is a possibility.
Fix #6706.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@38904 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Private libroot locking primitives:
- Reimplemented mutex to use the _kern_mutex*() syscalls.
- The initializer functions cannot fail anymore -- changed their return type
to void.
- Changed the initializer function semantics to not copy the name by default
anymore (as in the kernel). Also added *_etc() versions of them that take an
additional flags.
- Added static initializer macros.
- Made the mutex (and thus recursive_lock) lock functions non-interruptable.
- Got rid of the "lazy" version. They are no longer needed, since the
initialization of the standard types can be done statically and cannot fail.
* Adjusted libroot, runtime loader, and other code using the private libroot
locking primitives to the new semantics.
* pthreads mutexes and condition variables:
- Reimplemented using the _kern_mutex*() syscalls.
- Consistently use POSIX error codes.
- Fixed some not quite POSIX compliant behavior.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36323 a95241bf-73f2-0310-859d-f6bbb57e9c96

Replace semaphores/benaphores in the env, fork, and user/group code by lazy
mutexes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34340 a95241bf-73f2-0310-859d-f6bbb57e9c96

Moved the rld_export structure from <user_runtime.h> to
<runtime_loader.h>, since it isn't a kernel <-> userland interface.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28456 a95241bf-73f2-0310-859d-f6bbb57e9c96

* env.c -> env.cpp
* Squashed TODO: Use a benaphore for locking to improve performance.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27360 a95241bf-73f2-0310-859d-f6bbb57e9c96

libroot_debug: Merge guarded heap into libroot_debug.

The individual debug heap implementations are now exposed via a
structure of function pointers and a common frontend dispatches the
malloc and malloc_debug APIs through them.

The MALLOC_DEBUG environment variable can be used to select the guarded
heap by adding 'g', otherwise the debug heap is used as the default.
Consequently the separate libroot_guarded is not needed anymore and has
been removed.

To allow the use of environment variables this early, init_env_post_heap
has been added and the heap dependent atfork() moved there. This allowed
to fold the code of init_heap_post_env into init_heap so the former has
been removed.

Add private __getenv_reentrant()

A reentrant variant of getenv().

Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version

unsetenv() should remove *any* occurence of name=value.
As with putenv() both value and name can be modified afterwise in our
back, multiple occurence of the same name is a possibility.
Fix #6706.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@38904 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Private libroot locking primitives:
- Reimplemented mutex to use the _kern_mutex*() syscalls.
- The initializer functions cannot fail anymore -- changed their return type
to void.
- Changed the initializer function semantics to not copy the name by default
anymore (as in the kernel). Also added *_etc() versions of them that take an
additional flags.
- Added static initializer macros.
- Made the mutex (and thus recursive_lock) lock functions non-interruptable.
- Got rid of the "lazy" version. They are no longer needed, since the
initialization of the standard types can be done statically and cannot fail.
* Adjusted libroot, runtime loader, and other code using the private libroot
locking primitives to the new semantics.
* pthreads mutexes and condition variables:
- Reimplemented using the _kern_mutex*() syscalls.
- Consistently use POSIX error codes.
- Fixed some not quite POSIX compliant behavior.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36323 a95241bf-73f2-0310-859d-f6bbb57e9c96

Replace semaphores/benaphores in the env, fork, and user/group code by lazy
mutexes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34340 a95241bf-73f2-0310-859d-f6bbb57e9c96

Moved the rld_export structure from <user_runtime.h> to
<runtime_loader.h>, since it isn't a kernel <-> userland interface.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28456 a95241bf-73f2-0310-859d-f6bbb57e9c96

* env.c -> env.cpp
* Squashed TODO: Use a benaphore for locking to improve performance.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27360 a95241bf-73f2-0310-859d-f6bbb57e9c96