ctest: Honor tests-from-file options with empty input

If the `--tests-from-file` input file is empty, no tests should run.

Source/CTest/cmCTestTestHandler.cxx

@@ -347,6 +347,8 @@ void cmCTestTestHandler::Initialize()
   this->ExcludeFixtureCleanupRegExp.clear();
   this->TestListFile.clear();
   this->ExcludeTestListFile.clear();
+  this->TestsToRunByName.reset();
+  this->TestsToExcludeByName.reset();
 
   this->TestsToRunString.clear();
   this->UseUnion = false;
@@ -944,16 +946,16 @@ bool cmCTestTestHandler::ComputeTestList()
       }
     }
 
-    if (!this->TestsToRunByName.empty()) {
-      if (this->TestsToRunByName.find(tp.Name) ==
-          this->TestsToRunByName.end()) {
+    if (this->TestsToRunByName) {
+      if (this->TestsToRunByName->find(tp.Name) ==
+          this->TestsToRunByName->end()) {
         continue;
       }
     }
 
-    if (!this->TestsToExcludeByName.empty()) {
-      if (this->TestsToExcludeByName.find(tp.Name) !=
-          this->TestsToExcludeByName.end()) {
+    if (this->TestsToExcludeByName) {
+      if (this->TestsToExcludeByName->find(tp.Name) !=
+          this->TestsToExcludeByName->end()) {
         continue;
       }
     }
@@ -1845,13 +1847,15 @@ bool cmCTestTestHandler::GetListOfTests()
   }
 
   if (!this->TestListFile.empty()) {
-    if (!this->ReadTestListFile(this->TestListFile, this->TestsToRunByName)) {
+    this->TestsToRunByName = this->ReadTestListFile(this->TestListFile);
+    if (!this->TestsToRunByName) {
       return false;
     }
   }
   if (!this->ExcludeTestListFile.empty()) {
-    if (!this->ReadTestListFile(this->ExcludeTestListFile,
-                                this->TestsToExcludeByName)) {
+    this->TestsToExcludeByName =
+      this->ReadTestListFile(this->ExcludeTestListFile);
+    if (!this->TestsToExcludeByName) {
       return false;
     }
   }
@@ -2024,12 +2028,13 @@ void cmCTestTestHandler::ExpandTestsToRunInformationForRerunFailed()
   }
 }
 
-bool cmCTestTestHandler::ReadTestListFile(
-  std::string const& testListFileName, std::set<std::string>& testNames) const
+cm::optional<std::set<std::string>> cmCTestTestHandler::ReadTestListFile(
+  std::string const& testListFileName) const
 {
-  testNames.clear();
+  cm::optional<std::set<std::string>> result;
   cmsys::ifstream ifs(testListFileName.c_str());
   if (ifs) {
+    std::set<std::string> testNames;
     std::string line;
     while (cmSystemTools::GetLineFromStream(ifs, line)) {
       std::string trimmed = cmTrimWhitespace(line);
@@ -2039,17 +2044,14 @@ bool cmCTestTestHandler::ReadTestListFile(
 
       testNames.insert(trimmed);
     }
-    ifs.close();
-  } else if (!this->CTest->GetShowOnly() &&
-             !this->CTest->ShouldPrintLabels()) {
+    result = std::move(testNames);
+  } else {
     cmCTestLog(this->CTest, ERROR_MESSAGE,
                "Problem reading test list file: "
                  << testListFileName
                  << " while generating list of tests to run." << std::endl);
-    return false;
   }
-
-  return true;
+  return result;
 }
 
 void cmCTestTestHandler::RecordCustomTestMeasurements(cmXMLWriter& xml,

Source/CTest/cmCTestTestHandler.h

@@ -341,8 +341,8 @@ private:
   std::string GetTestStatus(cmCTestTestResult const&);
   void ExpandTestsToRunInformation(size_t numPossibleTests);
   void ExpandTestsToRunInformationForRerunFailed();
-  bool ReadTestListFile(std::string const& testListFileName,
-                        std::set<std::string>& testNames) const;
+  cm::optional<std::set<std::string>> ReadTestListFile(
+    std::string const& testListFileName) const;
 
   std::vector<std::string> CustomPreTest;
   std::vector<std::string> CustomPostTest;
@@ -363,8 +363,8 @@ private:
   cmsys::RegularExpression ExcludeTestsRegularExpression;
   std::string TestListFile;
   std::string ExcludeTestListFile;
-  std::set<std::string> TestsToRunByName;
-  std::set<std::string> TestsToExcludeByName;
+  cm::optional<std::set<std::string>> TestsToRunByName;
+  cm::optional<std::set<std::string>> TestsToExcludeByName;
 
   std::string ResourceSpecFile;
 

Tests/RunCMake/CTestCommandLine/RunCMakeTest.cmake

@@ -223,6 +223,8 @@ add_test(Test11 \"${CMAKE_COMMAND}\" -E echo \"test11\")
 endfunction()
 run_TestsFromFileTest(include --tests-from-file ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList.txt)
 run_TestsFromFileTest(exclude --exclude-from-file ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList.txt)
+run_TestsFromFileTest(include-empty --tests-from-file ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList-empty.txt)
+run_TestsFromFileTest(exclude-empty --exclude-from-file ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList-empty.txt)
 run_TestsFromFileTest(include-missing --tests-from-file ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList-missing.txt)
 run_TestsFromFileTest(exclude-missing --exclude-from-file ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList-missing.txt)
 

Tests/RunCMake/CTestCommandLine/TestsFromFile-exclude-empty-stdout.txt

@@ -0,0 +1,10 @@
+Test project [^
+]*/Tests/RunCMake/CTestCommandLine/TestsFromFile-exclude-empty
+ +Start 1: Test1
+1/3 Test #1: Test1 ............................   Passed +[0-9.]+ sec
+ +Start 2: Test2
+2/3 Test #2: Test2 ............................   Passed +[0-9.]+ sec
+ +Start 3: Test11
+3/3 Test #3: Test11 ...........................   Passed +[0-9.]+ sec
++
+100% tests passed, 0 tests failed out of 3

Tests/RunCMake/CTestCommandLine/TestsFromFile-include-empty-stderr.txt

@@ -0,0 +1 @@
+^No tests were found!!!$

Tests/RunCMake/ctest_test/RunCMakeTest.cmake

@@ -177,6 +177,8 @@ add_test(NAME Test11 COMMAND ${CMAKE_COMMAND} -E true)
 endfunction()
 run_tests_from_file(include INCLUDE_FROM_FILE ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList.txt)
 run_tests_from_file(exclude EXCLUDE_FROM_FILE ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList.txt)
+run_tests_from_file(include-empty INCLUDE_FROM_FILE ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList-empty.txt)
+run_tests_from_file(exclude-empty EXCLUDE_FROM_FILE ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList-empty.txt)
 run_tests_from_file(include-missing INCLUDE_FROM_FILE ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList-missing.txt)
 run_tests_from_file(exclude-missing EXCLUDE_FROM_FILE ${RunCMake_SOURCE_DIR}/TestsFromFile-TestList-missing.txt)
 

Tests/RunCMake/ctest_test/TestsFromFile-exclude-empty-stdout.txt

@@ -0,0 +1,12 @@
+Test project [^
+]*/Tests/RunCMake/ctest_test/TestsFromFile-exclude-empty-build
+ +Start 1: RunCMakeVersion
+1/4 Test #1: RunCMakeVersion ..................   Passed +[0-9.]+ sec
+ +Start 2: Test1
+2/4 Test #2: Test1 ............................   Passed +[0-9.]+ sec
+ +Start 3: Test2
+3/4 Test #3: Test2 ............................   Passed +[0-9.]+ sec
+ +Start 4: Test11
+4/4 Test #4: Test11 ...........................   Passed +[0-9.]+ sec
++
+100% tests passed, 0 tests failed out of 4

Tests/RunCMake/ctest_test/TestsFromFile-include-empty-result.txt

@@ -0,0 +1 @@
+(-1|255)

Tests/RunCMake/ctest_test/TestsFromFile-include-empty-stderr.txt

@@ -0,0 +1 @@
+^No tests were found!!!$