cmGlobalVisualStudioVersionedGenerator: Fix repeating SetGeneratorInstance

Fix logic added by commit 8917b8512f
(cmGlobalVisualStudioVersionedGenerator: Allow repeating
SetGeneratorInstance, 2021-10-20) to avoid repeating work.

2 files changed, 6 insertions, 2 deletions

diff --git a/Source/cmGlobalVisualStudioVersionedGenerator.cxx b/Source/cmGlobalVisualStudioVersionedGenerator.cxx
index ec2e74f..f27b2c4 100644
--- a/Source/cmGlobalVisualStudioVersionedGenerator.cxx
+++ b/Source/cmGlobalVisualStudioVersionedGenerator.cxx
@@ -436,9 +436,11 @@ bool cmGlobalVisualStudioVersionedGenerator::MatchesGeneratorName(
 bool cmGlobalVisualStudioVersionedGenerator::SetGeneratorInstance(
   std::string const& i, cmMakefile* mf)
 {
-  if (this->GeneratorInstance && i == *(this->GeneratorInstance)) {
+  if (this->LastGeneratorInstanceString &&
+      i == *(this->LastGeneratorInstanceString)) {
     return true;
   }
+
   if (!i.empty()) {
     if (!this->vsSetupAPIHelper.SetVSInstance(i)) {
       std::ostringstream e;
@@ -478,6 +480,8 @@ bool cmGlobalVisualStudioVersionedGenerator::SetGeneratorInstance(
   // The selected instance may have a different MSBuild than previously found.
   this->MSBuildCommandInitialized = false;
 
+  this->LastGeneratorInstanceString = i;
+
   return true;
 }
 
diff --git a/Source/cmGlobalVisualStudioVersionedGenerator.h b/Source/cmGlobalVisualStudioVersionedGenerator.h
index b7760ac..2aed65b 100644
--- a/Source/cmGlobalVisualStudioVersionedGenerator.h
+++ b/Source/cmGlobalVisualStudioVersionedGenerator.h
@@ -76,5 +76,5 @@ private:
   class Factory17;
   friend class Factory17;
   mutable cmVSSetupAPIHelper vsSetupAPIHelper;
-  cm::optional<std::string> GeneratorInstance;
+  cm::optional<std::string> LastGeneratorInstanceString;
 };