Since commit a13a5c948e (Replace use of CollapseCombinedPath with
CollapseFullPath, 2019-03-19, v3.15.0-rc1~361^2~1), one code path now
calls `CollapseFullPath` with a base path that may be relative.
Backport KWSys commit c6f8e24a3 (SystemTools: Fix CollapseFullPath with
relative base path, 2019-07-24) to handle such base paths.
This case occurs when a build tree is placed in a directory inside a
source tree such that CMake is willing to generate a relative path from
the build tree to the source tree. Add a test covering this case.
Fixes: #19507
The SystemTools::PutEnv function tries to provide the "putenv" API
without leaking memory. However, the kwsysDeletingCharVector singleton
frees memory that may still be referenced by the environment table,
having been placed there by putenv. If any static destruction or
processing by an external tool happens after the singleton is destroyed
and accesses the environment it will read invalid memory.
Replace use of putenv with setenv/unsetenv when available. The latter
manage internal copies of the values passed instead of referencing the
original memory. When setenv/unsetenv are not available use putenv with
a singleton that removes its values from the environment before freeing
their memory. This requires an "unputenv" implementation. On at least
some platforms it must be written in terms of "putenv" because other
APIs are not available and direct modification of the "environ" global
is not safe (e.g. on Windows there is interaction with "wenviron").
Fortunately either putenv("A=") or putenv("A") will remove "A" from the
environment on these platforms. On other platforms fall back to direct
manipulation of "environ".
Also add UnPutEnv to the API and add a test for the behavior of both.
This method replaces '//' with '/' to make the paths look nicer.
Originally it correctly skipped a leading '//' in a UNC path as the
comment says. However, commit "Removed extra variable initializations"
(2005-04-15) accidentally removed the "pos=1" initializer. It was then
incorrectly restored by commit "Added missing variable initialization"
(2005-04-15) as just "pos=0". Restore the proper initializer.
The test for this added by commit "better coverage" (2006-07-31)
included incorrect output for a sample UNC-like path. Fix it.
This converts the KWSys license to a pure 3-clause OSI-approved BSD
License. We drop the previous license clause requiring modified
versions to be plainly marked. We also update the KWSys copyright to
cover the full development time range.
