Restore support for explicitly referenced CMakeLists.txt sources

Since commit v3.11.0-rc1~467^2 (VS,Xcode: Add CMakeLists.txt sources
without mutating targets, 2017-10-18) we do not add `CMakeLists.txt` to
target sources but instead generate references to them directly.  This
broke projects that explicitly specify their `CMakeLists.txt` file as a
source file because the explicit entry is no longer consolidated with
the generated one.

Teach the relevant generators to avoid duplicating `CMakeLists.txt`
source references and add test cases.

Fixes: #17828

1 files changed, 12 insertions, 1 deletions

diff --git a/Source/cmLocalVisualStudio7Generator.cxx b/Source/cmLocalVisualStudio7Generator.cxx
index 98b1c44..13503ad 100644
--- a/Source/cmLocalVisualStudio7Generator.cxx
+++ b/Source/cmLocalVisualStudio7Generator.cxx
@@ -1347,7 +1347,18 @@ void cmLocalVisualStudio7Generator::WriteVCProjFile(std::ostream& fout,
       for (size_t ci = 0; ci < configs.size(); ++ci) {
         acs.Configs.push_back(ci);
       }
-      sources.Sources.emplace_back(std::move(acs));
+      bool haveCMakeLists = false;
+      for (cmGeneratorTarget::AllConfigSource& si : sources.Sources) {
+        if (si.Source == sf) {
+          haveCMakeLists = true;
+          // Replace the explicit source reference with our generated one.
+          si = acs;
+          break;
+        }
+      }
+      if (!haveCMakeLists) {
+        sources.Sources.emplace_back(std::move(acs));
+      }
     }
   }