Fix various warnings found by clang

- unused alias
- inefficient use of push_back
- exceptions not inheriting from std::exception
- weird use of a comma
- value compared against itself

apps/essimporter/main.cpp

@@ -57,7 +57,7 @@ int main(int argc, char** argv)
         else
         {
             const std::string& ext = ".omwsave";
-            if (boost::filesystem::exists(boost::filesystem::path(outputFile))
+            if (bfs::exists(bfs::path(outputFile))
                     && (outputFile.size() < ext.size() || outputFile.substr(outputFile.size()-ext.size()) != ext))
             {
                 throw std::runtime_error("Output file already exists and does not end in .omwsave. Did you mean to use --compare?");

apps/opencs/model/world/commands.cpp

@@ -76,6 +76,7 @@ void CSMWorld::ImportLandTexturesCommand::redo()
     }
 
     std::vector<std::string> oldTextures;
+    oldTextures.reserve(texIndices.size());
     for (int index : texIndices)
     {
         oldTextures.push_back(LandTexture::createUniqueRecordId(oldPlugin, index));

apps/opencs/model/world/idtree.cpp

@@ -201,7 +201,7 @@ QModelIndex CSMWorld::IdTree::parent (const QModelIndex& index) const
     const std::pair<int, int>& address(unfoldIndexAddress(id));
 
     if (address.first >= this->rowCount() || address.second >= this->columnCount())
-        throw "Parent index is not present in the model";
+        throw std::logic_error("Parent index is not present in the model");
 
     return createIndex(address.first, address.second);
 }
@@ -216,7 +216,7 @@ unsigned int CSMWorld::IdTree::foldIndexAddress (const QModelIndex& index) const
 std::pair< int, int > CSMWorld::IdTree::unfoldIndexAddress (unsigned int id) const
 {
     if (id == 0)
-        throw "Attempt to unfold index id of the top level data cell";
+        throw std::runtime_error("Attempt to unfold index id of the top level data cell");
 
     --id;
     int row = id / this->columnCount();

components/esm/loadregn.cpp

@@ -115,7 +115,7 @@ namespace ESM
     void Region::blank()
     {
         mData.mClear = mData.mCloudy = mData.mFoggy = mData.mOvercast = mData.mRain =
-            mData.mThunder = mData.mAsh, mData.mBlight = mData.mA = mData.mB = 0;
+            mData.mThunder = mData.mAsh = mData.mBlight = mData.mA = mData.mB = 0;
 
         mMapColor = 0;
 

components/esm/variantimp.cpp

@@ -52,12 +52,7 @@ void ESM::readESMVariantValue(ESMReader& esm, Variant::Format format, VarType ty
         esm.getHNT (value, "FLTV");
 
         if (type==VT_Short)
-        {
-            if (value!=value)
-                out = 0; // nan
-            else
             out = static_cast<short> (value);
-        }
         else if (type==VT_Long)
             out = static_cast<int> (value);
         else