5 files changed, 10 insertions, 12 deletions
diff --git a/Source/cmWhileCommand.cxx b/Source/cmWhileCommand.cxx
index b8297ce..a93a81f 100644
--- a/Source/cmWhileCommand.cxx
+++ b/Source/cmWhileCommand.cxx
@@ -79,12 +79,17 @@ bool cmWhileFunctionBlocker::Replay(std::vector<cmListFileFunction> functions,
     return out;
   };
 
+  // FIXME(#23296): For compatibility with older versions of CMake, we
+  // tolerate condition errors that evaluate to false.  We should add
+  // a policy to enforce such errors.
+  bool enforceError = true;
   std::string errorString;
   MessageType messageType;
 
   for (cmConditionEvaluator conditionEvaluator(mf, whileBT);
-       conditionEvaluator.IsTrue(expandArgs(this->Args, expandedArguments),
-                                 errorString, messageType);) {
+       (enforceError = /* enforce condition errors that evaluate to true */
+        conditionEvaluator.IsTrue(expandArgs(this->Args, expandedArguments),
+                                  errorString, messageType));) {
     // Invoke all the functions that were collected in the block.
     for (cmListFileFunction const& fn : functions) {
       cmExecutionStatus status(mf);
@@ -105,7 +110,7 @@ bool cmWhileFunctionBlocker::Replay(std::vector<cmListFileFunction> functions,
     }
   }
 
-  if (!errorString.empty()) {
+  if (!errorString.empty() && enforceError) {
     std::string err = "had incorrect arguments:\n ";
     for (auto const& i : expandedArguments) {
       err += " ";
diff --git a/Tests/RunCMake/while/unbalanced-parenthesis-result.txt b/Tests/RunCMake/while/unbalanced-parenthesis-result.txt
deleted file mode 100644
index d00491f..0000000
--- a/Tests/RunCMake/while/unbalanced-parenthesis-result.txt
+++ /dev/null
@@ -1 +0,0 @@
-1
diff --git a/Tests/RunCMake/while/unbalanced-parenthesis-stderr.txt b/Tests/RunCMake/while/unbalanced-parenthesis-stderr.txt
deleted file mode 100644
index ffa4fda..0000000
--- a/Tests/RunCMake/while/unbalanced-parenthesis-stderr.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-CMake Error at unbalanced-parenthesis.cmake:[0-9]+ \(while\):
-  had incorrect arguments:
-
-    "\("
-
-  mismatched parenthesis in condition
-Call Stack \(most recent call first\):
-  CMakeLists\.txt:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/while/unbalanced-parenthesis-stdout.txt b/Tests/RunCMake/while/unbalanced-parenthesis-stdout.txt
new file mode 100644
index 0000000..d45e194
--- /dev/null
+++ b/Tests/RunCMake/while/unbalanced-parenthesis-stdout.txt
@@ -0,0 +1 @@
+-- Code incorrectly accepted
diff --git a/Tests/RunCMake/while/unbalanced-parenthesis.cmake b/Tests/RunCMake/while/unbalanced-parenthesis.cmake
index 15322e0..39d736b 100644
--- a/Tests/RunCMake/while/unbalanced-parenthesis.cmake
+++ b/Tests/RunCMake/while/unbalanced-parenthesis.cmake
@@ -3,4 +3,5 @@ while(${paren})
   message(STATUS "Condition incorrectly true")
   break()
 endwhile()
+# FIXME(#23296): The above condition error is tolerated for compatibility.
 message(STATUS "Code incorrectly accepted")