find_program: Consider CWD only for paths with separator

find_program() incorrectly prepended search path components
to absolute file paths, and incorrectly searched the current
working directory for files that contained no directory
separators.

* Replace calls cmFindProgramHelper::CheckDirectory(std::string())
  with call of new method cmFindProgramHelper::CheckCompoundNames()
  that checks for the presence of a directory separator in the
  file name.
* Use cmSystemTools::CollapseCombinedPath rather than string
  concatenation to properly combine absolute file names with
  search path components.
* Add unit tests to verify corrections.

Fixes: #18044

4 files changed, 71 insertions, 0 deletions

diff --git a/Tests/RunCMake/find_program/RelAndAbsPath-stdout.txt b/Tests/RunCMake/find_program/RelAndAbsPath-stdout.txt
new file mode 100644
index 0000000..cb3c99f
--- /dev/null
+++ b/Tests/RunCMake/find_program/RelAndAbsPath-stdout.txt
@@ -0,0 +1,6 @@
+-- PROG_ABS='PROG_ABS-NOTFOUND'
+-- PROG_ABS_NPD='PROG_ABS_NPD-NOTFOUND'
+-- PROG_CWD='PROG_CWD-NOTFOUND'
+-- PROG_CWD_NPD='PROG_CWD_NPD-NOTFOUND'
+-- PROG_CWD_DOT='[^']*/Tests/RunCMake/find_program/testCWD'
+-- PROG_CWD_DOT_NPD='[^']*/Tests/RunCMake/find_program/testCWD'
diff --git a/Tests/RunCMake/find_program/RelAndAbsPath.cmake b/Tests/RunCMake/find_program/RelAndAbsPath.cmake
new file mode 100644
index 0000000..9a42c5e
--- /dev/null
+++ b/Tests/RunCMake/find_program/RelAndAbsPath.cmake
@@ -0,0 +1,63 @@
+# testNoSuchFile should only be found if the file absolute path is
+# incorrectly prepended with the search path.
+
+function(strip_windows_path_prefix p outvar)
+    if(CMAKE_HOST_SYSTEM_NAME MATCHES "Windows")
+        string(REGEX REPLACE "^.:" "" p "${p}")
+    endif()
+    set(${outvar} "${p}" PARENT_SCOPE)
+endfunction()
+
+strip_windows_path_prefix("${CMAKE_CURRENT_SOURCE_DIR}" srcdir)
+
+file(MAKE_DIRECTORY "tmp${srcdir}")
+configure_file(testCWD "tmp${srcdir}/testNoSuchFile" COPYONLY)
+
+find_program(PROG_ABS
+  NAMES "${srcdir}/testNoSuchFile"
+  PATHS "${CMAKE_CURRENT_BINARY_DIR}/tmp"
+  NO_DEFAULT_PATH
+  )
+message(STATUS "PROG_ABS='${PROG_ABS}'")
+
+find_program(PROG_ABS_NPD
+  NAMES "${srcdir}/testNoSuchFile"
+  PATHS "${CMAKE_CURRENT_BINARY_DIR}/tmp"
+  NAMES_PER_DIR
+  NO_DEFAULT_PATH
+  )
+message(STATUS "PROG_ABS_NPD='${PROG_ABS_NPD}'")
+
+# ./testCWD should not be found without '.' being in the path list.
+
+configure_file(testCWD testCWD COPYONLY)
+
+find_program(PROG_CWD
+  NAMES testCWD
+  NO_DEFAULT_PATH
+  )
+message(STATUS "PROG_CWD='${PROG_CWD}'")
+
+find_program(PROG_CWD_NPD
+  NAMES testCWD
+  NAMES_PER_DIR
+  NO_DEFAULT_PATH
+  )
+message(STATUS "PROG_CWD_NPD='${PROG_CWD_NPD}'")
+
+# Confirm that adding '.' to path does locate ./testCWD.
+
+find_program(PROG_CWD_DOT
+  NAMES testCWD
+  PATHS .
+  NO_DEFAULT_PATH
+  )
+message(STATUS "PROG_CWD_DOT='${PROG_CWD_DOT}'")
+
+find_program(PROG_CWD_DOT_NPD
+  NAMES testCWD
+  PATHS .
+  NAMES_PER_DIR
+  NO_DEFAULT_PATH
+  )
+message(STATUS "PROG_CWD_DOT_NPD='${PROG_CWD_DOT_NPD}'")
diff --git a/Tests/RunCMake/find_program/RunCMakeTest.cmake b/Tests/RunCMake/find_program/RunCMakeTest.cmake
index 89307c1..6903f05 100644
--- a/Tests/RunCMake/find_program/RunCMakeTest.cmake
+++ b/Tests/RunCMake/find_program/RunCMakeTest.cmake
@@ -3,6 +3,7 @@ include(RunCMake)
 run_cmake(EnvAndHints)
 run_cmake(DirsPerName)
 run_cmake(NamesPerDir)
+run_cmake(RelAndAbsPath)
 
 if(CMAKE_SYSTEM_NAME MATCHES "^(Windows|CYGWIN)$")
   run_cmake(WindowsCom)
diff --git a/Tests/RunCMake/find_program/testCWD b/Tests/RunCMake/find_program/testCWD
new file mode 100755
index 0000000..1a24852
--- /dev/null
+++ b/Tests/RunCMake/find_program/testCWD
@@ -0,0 +1 @@
+#!/bin/sh