3 files changed, 22 insertions, 16 deletions
diff --git a/Source/cmake.cxx b/Source/cmake.cxx
index 1aff5eb..74542df 100644
--- a/Source/cmake.cxx
+++ b/Source/cmake.cxx
@@ -609,16 +609,13 @@ bool cmake::FindPackage(const std::vector<std::string>& args)
 }
 
 // Parse the args
-void cmake::SetArgs(const std::vector<std::string>& args,
-                    bool directoriesSetBefore)
+void cmake::SetArgs(const std::vector<std::string>& args)
 {
-  bool directoriesSet = directoriesSetBefore;
   bool haveToolset = false;
   bool havePlatform = false;
   for (unsigned int i = 1; i < args.size(); ++i) {
     std::string const& arg = args[i];
     if (arg.find("-H", 0) == 0 || arg.find("-S", 0) == 0) {
-      directoriesSet = true;
       std::string path = arg.substr(2);
       if (path.empty()) {
         ++i;
@@ -639,7 +636,6 @@ void cmake::SetArgs(const std::vector<std::string>& args,
     } else if (arg.find("-O", 0) == 0) {
       // There is no local generate anymore.  Ignore -O option.
     } else if (arg.find("-B", 0) == 0) {
-      directoriesSet = true;
       std::string path = arg.substr(2);
       if (path.empty()) {
         ++i;
@@ -801,16 +797,27 @@ void cmake::SetArgs(const std::vector<std::string>& args,
         this->SetGlobalGenerator(gen);
       }
     }
-    // no option assume it is the path to the source
+    // no option assume it is the path to the source or an existing build
     else {
-      directoriesSet = true;
       this->SetDirectoriesFromFile(arg.c_str());
     }
   }
-  if (!directoriesSet) {
-    this->SetHomeOutputDirectory(cmSystemTools::GetCurrentWorkingDirectory());
+
+  const bool haveSourceDir = !this->GetHomeDirectory().empty();
+  const bool haveBinaryDir = !this->GetHomeOutputDirectory().empty();
+
+  if (this->CurrentWorkingMode == cmake::NORMAL_MODE && !haveSourceDir &&
+      !haveBinaryDir) {
+    cmSystemTools::Error("No source or binary directory provided");
+    return;
+  }
+
+  if (!haveSourceDir) {
     this->SetHomeDirectory(cmSystemTools::GetCurrentWorkingDirectory());
   }
+  if (!haveBinaryDir) {
+    this->SetHomeOutputDirectory(cmSystemTools::GetCurrentWorkingDirectory());
+  }
 }
 
 void cmake::SetDirectoriesFromFile(const char* arg)
diff --git a/Source/cmake.h b/Source/cmake.h
index d3d0e80..5bca306 100644
--- a/Source/cmake.h
+++ b/Source/cmake.h
@@ -275,8 +275,7 @@ public:
   int GetSystemInformation(std::vector<std::string>&);
 
   ///! Parse command line arguments
-  void SetArgs(const std::vector<std::string>&,
-               bool directoriesSetBefore = false);
+  void SetArgs(const std::vector<std::string>& args);
 
   ///! Is this cmake running as a result of a TRY_COMPILE command
   bool GetIsInTryCompile() const;
diff --git a/Source/cmakemain.cxx b/Source/cmakemain.cxx
index 75dabde..e52f2b3 100644
--- a/Source/cmakemain.cxx
+++ b/Source/cmakemain.cxx
@@ -285,12 +285,12 @@ int do_cmake(int ac, char const* const* av)
     } else if (cmHasLiteralPrefix(av[i], "-P")) {
       if (i == ac - 1) {
         cmSystemTools::Error("No script specified for argument -P");
-      } else {
-        workingMode = cmake::SCRIPT_MODE;
-        args.push_back(av[i]);
-        i++;
-        args.push_back(av[i]);
+        return 1;
       }
+      workingMode = cmake::SCRIPT_MODE;
+      args.push_back(av[i]);
+      i++;
+      args.push_back(av[i]);
     } else if (cmHasLiteralPrefix(av[i], "--find-package")) {
       workingMode = cmake::FIND_PACKAGE_MODE;
       args.push_back(av[i]);