Add new event handlers to a staging area

This reverts the semantical change in commit 61ccf2f that event handlers
registered as a result of an event received that event.

Compared with commit 3d8c29bc, this is a lower-level way to fix the ;
character appearing in the command console. This commit has potential to
fix more code that assumes that an event handler can't receive an event
that caused the handler to be registered in the first place. On the other
hand, it is no longer possible for event handlers to receive such events
even if developers want that.

changelog

@@ -55,6 +55,7 @@ Version 1.13.5+dev:
      high HP, drain, slow, berserk, etc.) it's significantly faster than the default
      damage calculation method.
 * Miscellaneous and bug fixes:
+   * Fixed a stray ; character appearing pre-entered in the command console.
    * Fixed bug in wesnothd that was causing server crashes if game with
      multiple network and local players was ran.
    * Added a tab to run the wmlxgettext tool to GUI.pyw

players_changelog

@@ -18,6 +18,8 @@ Version 1.13.5+dev:
      probabilities. This method is inexact, but in very complex battles (extremely
      high HP, drain, slow, berserk, etc.) it's significantly faster than the default
      damage calculation method.
+ * Miscellaneous and bug fixes:
+   * Fixed a stray ; character appearing pre-entered in the command console.
 
 Version 1.13.5:
  * Campaigns:

src/events.cpp

@@ -34,6 +34,7 @@
 #include <utility>
 #include <vector>
 #include <algorithm>
+#include <iterator>
 #include <boost/thread.hpp>
 
 #define ERR_GEN LOG_STREAM(err, lg::general)
@@ -43,7 +44,10 @@ namespace events
 
 void context::add_handler(sdl_handler* ptr)
 {
-	handlers.push_back(ptr);
+	/* Add new handlers to the staging list initially.
+	This ensures that if an event handler adds more handlers, the new handlers
+	won't be called for the event that caused them to be added. */
+	staging_handlers.push_back(ptr);
 }
 
 bool context::remove_handler(sdl_handler* ptr)
@@ -68,7 +72,18 @@ bool context::remove_handler(sdl_handler* ptr)
 
 		if(i == handlers.end()) {
 			--depth;
-			return false;
+
+			// The handler may be in the staging area. Search it from there.
+			auto j = std::find(staging_handlers.begin(), staging_handlers.end(), ptr);
+			if (j != staging_handlers.end())
+			{
+				staging_handlers.erase(j);
+				return true;
+			}
+			else
+			{
+				return false;
+			}
 		}
 
 		if(i == focused_handler) {
@@ -131,6 +146,12 @@ void context::set_focus(const sdl_handler* ptr)
 	}
 }
 
+void context::add_staging_handlers()
+{
+	std::copy(staging_handlers.begin(), staging_handlers.end(), std::back_inserter(handlers));
+	staging_handlers.clear();
+}
+
 context::~context()
 {
 	for (sdl_handler* h : handlers)
@@ -445,6 +466,11 @@ void pump()
 	ev_end = events.end();
 
 	for(ev_it = events.begin(); ev_it != ev_end; ++ev_it){
+		for (context& c : event_contexts)
+		{
+			c.add_staging_handlers();
+		}
+
 		SDL_Event &event = *ev_it;
 		switch(event.type) {
 

src/events.hpp

@@ -41,7 +41,8 @@ class context
 public:
 	context() :
 		handlers(),
-		focused_handler(handlers.end())
+		focused_handler(handlers.end()),
+		staging_handlers()
 	{
 	}
 
@@ -53,9 +54,11 @@ public:
 	bool remove_handler(sdl_handler* ptr);
 	void cycle_focus();
 	void set_focus(const sdl_handler* ptr);
+	void add_staging_handlers();
 
 	handler_list handlers;
 	handler_list::iterator focused_handler;
+	std::vector<sdl_handler*> staging_handlers;
 };
 
 //any classes that derive from this class will automatically