foreach(): loop variables are only available in the loop scope

Fixes: #20553

3 files changed, 106 insertions, 0 deletions

diff --git a/Tests/RunCMake/foreach/RunCMakeTest.cmake b/Tests/RunCMake/foreach/RunCMakeTest.cmake
index d3f7c23..15ca477 100644
--- a/Tests/RunCMake/foreach/RunCMakeTest.cmake
+++ b/Tests/RunCMake/foreach/RunCMakeTest.cmake
@@ -20,3 +20,5 @@ run_cmake(foreach-RANGE-non-int-test-3-2)
 run_cmake(foreach-RANGE-non-int-test-3-3)
 run_cmake(foreach-RANGE-invalid-test)
 run_cmake(foreach-RANGE-out-of-range-test)
+run_cmake(foreach-var-scope-CMP0124-OLD)
+run_cmake(foreach-var-scope-CMP0124-NEW)
diff --git a/Tests/RunCMake/foreach/foreach-var-scope-CMP0124-NEW.cmake b/Tests/RunCMake/foreach/foreach-var-scope-CMP0124-NEW.cmake
new file mode 100644
index 0000000..7e2eee0
--- /dev/null
+++ b/Tests/RunCMake/foreach/foreach-var-scope-CMP0124-NEW.cmake
@@ -0,0 +1,51 @@
+
+cmake_policy(SET CMP0124 NEW)
+
+foreach(VAR a b c)
+endforeach()
+if (DEFINED VAR)
+  message(SEND_ERROR "Variable 'VAR' unexpectedly defined.")
+endif()
+
+set(LIST1 a b c)
+set(LIST2 x y z)
+foreach(VAR1_1 VAR1_2 IN ZIP_LISTS LIST1 LIST2)
+endforeach()
+if (DEFINED VAR1_1 OR DEFINED VAR1_2)
+  message(SEND_ERROR "Variables 'VAR1_1' or 'VAR1_2' unexpectedly defined.")
+endif()
+
+
+set (VAR2 OLD)
+foreach(VAR2 a b c)
+endforeach()
+if (NOT DEFINED VAR2 OR NOT VAR2 STREQUAL "OLD")
+  message(SEND_ERROR "Variable 'VAR2' not defined or wrong value.")
+endif()
+
+set (VAR2_2 OLD)
+foreach(VAR2_1 VAR2_2 IN ZIP_LISTS LIST1 LIST2)
+endforeach()
+if (DEFINED VAR2_1 OR NOT DEFINED VAR2_2)
+  message(SEND_ERROR "Variable 'VAR2_1' unexpectedly defined or variable 'VAR2_2' not defined.")
+endif()
+
+
+set (VAR3 OLD CACHE STRING "")
+foreach(VAR3 a b c)
+endforeach()
+# check that only cache variable is defined
+set(OLD_VALUE "${VAR3}")
+unset(VAR3 CACHE)
+if (DEFINED VAR3 OR NOT OLD_VALUE STREQUAL "OLD")
+  message(SEND_ERROR "Variable 'VAR3' wrongly defined or wrong value.")
+endif()
+
+set (VAR3_2 OLD CACHE STRING "")
+foreach(VAR3_1 VAR3_2 IN ZIP_LISTS LIST1 LIST2)
+endforeach()
+set(OLD_VALUE "${VAR3_2}")
+unset(VAR3_2 CACHE)
+if (DEFINED VAR3_1 OR DEFINED VAR3_2 OR NOT OLD_VALUE STREQUAL "OLD")
+  message(SEND_ERROR "Variable 'VAR3_1' unexpectedly defined or variable 'VAR2_2' wrongly defined or wrong value.")
+endif()
diff --git a/Tests/RunCMake/foreach/foreach-var-scope-CMP0124-OLD.cmake b/Tests/RunCMake/foreach/foreach-var-scope-CMP0124-OLD.cmake
new file mode 100644
index 0000000..f955982
--- /dev/null
+++ b/Tests/RunCMake/foreach/foreach-var-scope-CMP0124-OLD.cmake
@@ -0,0 +1,53 @@
+
+cmake_policy(SET CMP0124 OLD)
+
+foreach(VAR a b c)
+endforeach()
+if (NOT DEFINED VAR OR NOT VAR STREQUAL "")
+  message(SEND_ERROR "Variable 'VAR' not defined or wrong value.")
+endif()
+
+set(LIST1 a b c)
+set(LIST2 x y z)
+foreach(VAR1_1 VAR1_2 IN ZIP_LISTS LIST1 LIST2)
+endforeach()
+if (NOT DEFINED VAR1_1 OR NOT VAR1_1 STREQUAL ""
+    OR NOT DEFINED VAR1_2 OR NOT VAR1_2 STREQUAL "")
+  message(SEND_ERROR "Variables 'VAR1_1' or 'VAR1_2' not defined or wrong value.")
+endif()
+
+
+set (VAR2 OLD)
+foreach(VAR2 a b c)
+endforeach()
+if (NOT DEFINED VAR2 OR NOT VAR2 STREQUAL "OLD")
+  message(SEND_ERROR "Variable 'VAR2' not defined or wrong value.")
+endif()
+
+set (VAR2_2 OLD)
+foreach(VAR2_1 VAR2_2 IN ZIP_LISTS LIST1 LIST2)
+endforeach()
+if (NOT DEFINED VAR2_1 OR NOT VAR2_1 STREQUAL ""
+    OR NOT DEFINED VAR2_2 OR NOT VAR2_2 STREQUAL "OLD")
+  message(SEND_ERROR "Variables 'VAR2_1' or 'VAR2_2' not defined or wrong value.")
+endif()
+
+
+set (VAR3 OLD CACHE STRING "")
+foreach(VAR3 a b c)
+endforeach()
+# a normal variable is defined, holding cache variable value
+unset(VAR3 CACHE)
+if (NOT DEFINED VAR3 OR NOT VAR3 STREQUAL "OLD")
+  message(SEND_ERROR "Variable 'VAR3' not defined or wrong value.")
+endif()
+
+set (VAR3_2 OLD CACHE STRING "")
+foreach(VAR3_1 VAR3_2 IN ZIP_LISTS LIST1 LIST2)
+endforeach()
+# a normal variable is defined, holding cache variable value
+unset(VAR3_2 CACHE)
+if (NOT DEFINED VAR3_1 OR NOT VAR3_1 STREQUAL ""
+    OR NOT DEFINED VAR3_2 OR NOT VAR3_2 STREQUAL "OLD")
+  message(SEND_ERROR "Variables 'VAR3_1' or 'VAR3_2' not defined or wrong value.")
+endif()