fix potential crash on exit in REAPER < 6.67 due to API registration keys being invalidated

Fixes #56

Author: cfillion

src/api.cpp

@@ -29,21 +29,14 @@ APIReg::APIReg(const APIFunc *func)
   : m_func(func),
     m_impl(KEY("API")), m_vararg(KEY("APIvararg")), m_help(KEY("APIdef"))
 {
-  registerFunc();
+  plugin_register(m_impl.c_str(), m_func->cImpl);
+  plugin_register(m_vararg.c_str(), m_func->reascriptImpl);
+  plugin_register(m_help.c_str(), m_func->definition);
 }
 
 APIReg::~APIReg()
 {
-  m_impl.insert(m_impl.begin(), '-');
-  m_vararg.insert(m_vararg.begin(), '-');
-  m_help.insert(m_help.begin(), '-');
-
-  registerFunc();
-}
-
-void APIReg::registerFunc() const
-{
-  plugin_register(m_impl.c_str(), m_func->cImpl);
-  plugin_register(m_vararg.c_str(), m_func->reascriptImpl);
-  plugin_register(m_help.c_str(), m_func->definition);
+  plugin_register(("-" + m_impl).c_str(), m_func->cImpl);
+  plugin_register(("-" + m_vararg).c_str(), m_func->reascriptImpl);
+  plugin_register(("-" + m_help).c_str(), m_func->definition);
 }

src/api.hpp

@@ -34,11 +34,9 @@ class APIReg {
   ~APIReg();
 
 private:
-  void registerFunc() const;
-
   const APIFunc *m_func;
 
-  // plugin_register requires these to not be temporaries
+  // REAPER < 6.67 requires these strings to remain valid after registering
   std::string m_impl;
   std::string m_vararg;
   std::string m_help;