find_(library|file|path): Drop PATH-derived search prefixes

Since commit ffc06c1239 (Teach find_(library|file|path) to get prefixes
from PATH, 2015-02-18, v3.3.0-rc1~430^2) we search in `<prefix>/include`
and `<prefix>/lib` directories for prefixes with `bin` directories in
the `PATH` environment variable.  The motivation was to search the
installation prefixes of MSYS and MinGW development environments
automatically.

This behavior can search undesired prefixes that happen to be in the
`PATH` for unrelated reasons.  It was reverted for non-Windows hosts
within a year by commit b30b32a493 (Drop find_(library|file|path)
prefixes from PATH on non-Windows, 2016-05-09, v3.6.0-rc1~82^2) but was
kept on Windows hosts to support its motivating use case.  However,
similar problems have since been observed on Windows.  For example,
commit 955d6245c1 (MSVC: Revert "Teach find_library to consider the
'libfoo.a' naming convention", 2022-11-28, v3.25.1~6^2) was primarily
due to undesired discovery of libraries in `PATH`-derived prefixes.

Since commit 5e5132e1b1 (MinGW: Search for packages in standard MSYSTEM
environment prefixes, 2023-09-11) we search MSYS and MinGW environments'
prefixes explicitly, so `PATH`-derived prefixes are no longer needed for
the original motivating use case.

Fixes: #24216

1 files changed, 0 insertions, 3 deletions

diff --git a/Source/cmFindBase.cxx b/Source/cmFindBase.cxx
index 9f78418..8840cdc 100644
--- a/Source/cmFindBase.cxx
+++ b/Source/cmFindBase.cxx
@@ -329,9 +329,6 @@ void cmFindBase::FillSystemEnvironmentPath()
   // Add LIB or INCLUDE
   if (!this->EnvironmentPath.empty()) {
     paths.AddEnvPath(this->EnvironmentPath);
-#if defined(_WIN32) || defined(__CYGWIN__)
-    paths.AddEnvPrefixPath("PATH", true);
-#endif
   }
   // Add PATH
   paths.AddEnvPath("PATH");