From 56eaeca01cc71df32947cfa65b3987f15339d207 Mon Sep 17 00:00:00 2001
From: heckflosse <heckflosse67@gmx.de>
Date: Wed, 12 Jul 2017 18:47:50 +0200
Subject: [PATCH] Limit number of open editors on Windows depending on
 available gdi handles to avoid crashes. Fixes #3937

---
 rtdata/languages/default |  1 +
 rtgui/filepanel.cc       | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/rtdata/languages/default b/rtdata/languages/default
index 9eea6dc17..51024db25 100644
--- a/rtdata/languages/default
+++ b/rtdata/languages/default
@@ -783,6 +783,7 @@ MAIN_MSG_OPERATIONCANCELLED;Operation cancelled
 MAIN_MSG_PATHDOESNTEXIST;The path\n\n<b>%1</b>\n\ndoes not exist. Please set a correct path in Preferences.
 MAIN_MSG_QOVERWRITE;Do you want to overwrite it?
 MAIN_MSG_SETPATHFIRST;You first have to set a target path in Preferences in order to use this function!
+MAIN_MSG_TOOMANYOPENEDITORS;Too many open editors.\nPlease close an editor to continue.
 MAIN_MSG_WRITEFAILED;Failed to write\n<b>"%1"</b>\n\nMake sure that the folder exists and that you have write permission to it.
 MAIN_TAB_COLOR;Color
 MAIN_TAB_COLOR_TOOLTIP;Shortcut: <b>Alt-c</b>
diff --git a/rtgui/filepanel.cc b/rtgui/filepanel.cc
index 7d0f9013b..b3e3668c5 100644
--- a/rtgui/filepanel.cc
+++ b/rtgui/filepanel.cc
@@ -279,9 +279,23 @@ bool FilePanel::imageLoaded( Thumbnail* thm, ProgressConnector<rtengine::Initial
             if (options.tabbedUI) {
                 EditorPanel* epanel;
                 {
+#ifdef WIN32
+                    int winGdiHandles = GetGuiResources( GetCurrentProcess(), GR_GDIOBJECTS);
+                    if(winGdiHandles > 0 && winGdiHandles <= 8500) // 0 means we don't have the rights to access the function, 8500 because the limit is 10000 and we need about 1500 free handles
+#endif
+                    {
                     GThreadLock lock; // Acquiring the GUI... not sure that it's necessary, but it shouldn't harm
                     epanel = Gtk::manage (new EditorPanel ());
                     parent->addEditorPanel (epanel, pl->thm->getFileName());
+                    }
+#ifdef WIN32
+                    else {
+                        Glib::ustring msg_ = Glib::ustring("<b>") + M("MAIN_MSG_CANNOTLOAD") + " \"" + thm->getFileName() + "\" .\n" + M("MAIN_MSG_TOOMANYOPENEDITORS") + "</b>";
+                        Gtk::MessageDialog msgd (msg_, true, Gtk::MESSAGE_ERROR, Gtk::BUTTONS_OK, true);
+                        msgd.run ();
+                        goto MAXGDIHANDLESREACHED;
+                    }
+#endif
                 }
                 epanel->open(pl->thm, pl->pc->returnValue() );
 
@@ -301,7 +315,9 @@ bool FilePanel::imageLoaded( Thumbnail* thm, ProgressConnector<rtengine::Initial
             Gtk::MessageDialog msgd (msg_, true, Gtk::MESSAGE_ERROR, Gtk::BUTTONS_OK, true);
             msgd.run ();
         }
-
+#ifdef WIN32
+MAXGDIHANDLESREACHED:
+#endif
         delete pl->pc;
 
         {