cmVisualStudioSlnParser: Fix storage of some `.sln` parse results

In commit 5cdd774d51 (VS: Handle build target correct for .NET SDK style
projects with Any CPU, 2022-02-02, v3.23.0-rc1~3^2), some parse results
were stored in temporary copies of `cmSlnProjectEntry` and thrown away.

Source/cmGlobalVisualStudio10Generator.cxx

@@ -1131,8 +1131,7 @@ cmGlobalVisualStudio10Generator::GenerateBuildCommand(
       std::string targetProject = cmStrCat(tname, ".vcxproj");
       if (targetProject.find('/') == std::string::npos) {
         // it might be in a subdir
-        if (cm::optional<cmSlnProjectEntry> proj =
-              slnData.GetProjectByName(tname)) {
+        if (cmSlnProjectEntry const* proj = slnData.GetProjectByName(tname)) {
           targetProject = proj->GetRelativePath();
           cmSystemTools::ConvertToUnixSlashes(targetProject);
         }

Source/cmVisualStudioSlnData.cxx

@@ -16,29 +16,32 @@ void cmSlnProjectEntry::AddProjectConfiguration(
 }
 
 std::string cmSlnProjectEntry::GetProjectConfiguration(
-  std::string const& solutionConfiguration)
+  std::string const& solutionConfiguration) const
 {
-  return projectConfigurationMap[solutionConfiguration];
+  auto i = projectConfigurationMap.find(solutionConfiguration);
+  if (i != projectConfigurationMap.end()) {
+    return i->second;
+  }
+  return {};
 }
 
-cm::optional<cmSlnProjectEntry> cmSlnData::GetProjectByGUID(
-  std::string const& projectGUID) const
+cmSlnProjectEntry* cmSlnData::GetProjectByGUID(std::string const& projectGUID)
 {
   auto it(ProjectsByGUID.find(projectGUID));
   if (it != ProjectsByGUID.end()) {
-    return it->second;
+    return &it->second;
   }
-  return cm::nullopt;
+  return nullptr;
 }
 
-cm::optional<cmSlnProjectEntry> cmSlnData::GetProjectByName(
+cmSlnProjectEntry const* cmSlnData::GetProjectByName(
   std::string const& projectName) const
 {
   auto it(ProjectNameIndex.find(projectName));
   if (it != ProjectNameIndex.end()) {
-    return it->second->second;
+    return &it->second->second;
   }
-  return cm::nullopt;
+  return nullptr;
 }
 
 std::vector<cmSlnProjectEntry> cmSlnData::GetProjects() const
@@ -75,7 +78,7 @@ std::string cmSlnData::GetConfigurationTarget(
 {
   std::string solutionTarget =
     cmStrCat(solutionConfiguration, '|', platformName);
-  cm::optional<cmSlnProjectEntry> project = GetProjectByName(projectName);
+  cmSlnProjectEntry const* project = GetProjectByName(projectName);
   if (!project) {
     return platformName;
   }

Source/cmVisualStudioSlnData.h

@@ -8,8 +8,6 @@
 #include <string>
 #include <vector>
 
-#include <cm/optional>
-
 class cmSlnProjectEntry
 {
 public:
@@ -30,7 +28,7 @@ public:
                                std::string const& projectConfiguration);
 
   std::string GetProjectConfiguration(
-    std::string const& solutionConfiguration);
+    std::string const& solutionConfiguration) const;
 
 private:
   std::string Guid, Name, RelativePath;
@@ -56,10 +54,9 @@ public:
     minimumVisualStudioVersion = version;
   }
 
-  cm::optional<cmSlnProjectEntry> GetProjectByGUID(
-    std::string const& projectGUID) const;
+  cmSlnProjectEntry* GetProjectByGUID(std::string const& projectGUID);
 
-  cm::optional<cmSlnProjectEntry> GetProjectByName(
+  cmSlnProjectEntry const* GetProjectByName(
     std::string const& projectName) const;
 
   std::vector<cmSlnProjectEntry> GetProjects() const;

Source/cmVisualStudioSlnParser.cxx

@@ -320,8 +320,7 @@ bool cmVisualStudioSlnParser::State::Process(
         std::string guid = tagElements[0];
         std::string solutionConfiguration = tagElements[1];
         std::string activeBuild = tagElements[2];
-        cm::optional<cmSlnProjectEntry> projectEntry =
-          output.GetProjectByGUID(guid);
+        cmSlnProjectEntry* projectEntry = output.GetProjectByGUID(guid);
 
         if (!projectEntry) {
           result.SetError(ResultErrorInputStructure, this->GetCurrentLine());