diff --git a/direct/src/dist/commands.py b/direct/src/dist/commands.py
index 948891d19d..e5d9ac4f72 100644
--- a/direct/src/dist/commands.py
+++ b/direct/src/dist/commands.py
@@ -13,6 +13,7 @@ import stat
 import struct
 import imp
 import string
+import time
 
 import setuptools
 import distutils.log
@@ -30,6 +31,15 @@ if sys.version_info < (3, 0):
     # Python 3 defines these subtypes of IOError, but Python 2 doesn't.
     FileNotFoundError = IOError
 
+    # Warn the user.  They might be using Python 2 by accident.
+    print("=================================================================")
+    print("WARNING: You are using Python 2, which will soon be discontinued.")
+    print("WARNING: Please use Python 3 for best results and continued")
+    print("WARNING: support after the EOL date of December 31st, 2019.")
+    print("=================================================================")
+    sys.stdout.flush()
+    time.sleep(4.0)
+
 
 def _parse_list(input):
     if isinstance(input, basestring):
@@ -229,7 +239,9 @@ class build_apps(setuptools.Command):
         self.requirements_path = os.path.join(os.getcwd(), 'requirements.txt')
         self.use_optimized_wheels = True
         self.optimized_wheel_index = ''
-        self.pypi_extra_indexes = []
+        self.pypi_extra_indexes = [
+            'https://archive.panda3d.org/thirdparty',
+        ]
         self.file_handlers = {}
         self.exclude_dependencies = [
             # Windows
diff --git a/direct/src/filter/FilterManager.py b/direct/src/filter/FilterManager.py
index 4150cba568..5696ac9460 100644
--- a/direct/src/filter/FilterManager.py
+++ b/direct/src/filter/FilterManager.py
@@ -124,7 +124,7 @@ class FilterManager(DirectObject):
 
         return winx,winy
 
-    def renderSceneInto(self, depthtex=None, colortex=None, auxtex=None, auxbits=0, textures=None):
+    def renderSceneInto(self, depthtex=None, colortex=None, auxtex=None, auxbits=0, textures=None, fbprops=None):
 
         """ Causes the scene to be rendered into the supplied textures
         instead of into the original window.  Puts a fullscreen quad
@@ -185,7 +185,10 @@ class FilterManager(DirectObject):
         # Choose the size of the offscreen buffer.
 
         (winx, winy) = self.getScaledSize(1,1,1)
-        buffer = self.createBuffer("filter-base", winx, winy, texgroup)
+        if fbprops is not None:
+            buffer = self.createBuffer("filter-base", winx, winy, texgroup, fbprops=fbprops)
+        else:
+            buffer = self.createBuffer("filter-base", winx, winy, texgroup)
 
         if (buffer == None):
             return None
@@ -287,7 +290,7 @@ class FilterManager(DirectObject):
 
         return quad
 
-    def createBuffer(self, name, xsize, ysize, texgroup, depthbits=1):
+    def createBuffer(self, name, xsize, ysize, texgroup, depthbits=1, fbprops=None):
         """ Low-level buffer creation.  Not intended for public use. """
 
         winprops = WindowProperties()
@@ -297,6 +300,9 @@ class FilterManager(DirectObject):
         props.setRgbColor(1)
         props.setDepthBits(depthbits)
         props.setStereo(self.win.isStereo())
+        if fbprops is not None:
+            props.addProperties(fbprops)
+
         depthtex, colortex, auxtex0, auxtex1 = texgroup
         if (auxtex0 != None):
             props.setAuxRgba(1)
diff --git a/direct/src/showbase/ShowBase.py b/direct/src/showbase/ShowBase.py
index 2d32d2b338..041c2fc40a 100644
--- a/direct/src/showbase/ShowBase.py
+++ b/direct/src/showbase/ShowBase.py
@@ -1677,13 +1677,17 @@ class ShowBase(DirectObject.DirectObject):
         return self.mouseWatcherNode.getModifierButtons().isDown(
             KeyboardButton.meta())
 
-    def attachInputDevice(self, device, prefix=None):
+    def attachInputDevice(self, device, prefix=None, gui=False):
         """
         This function attaches an input device to the data graph, which will
         cause the device to be polled and generate events.  If a prefix is
         given and not None, it is used to prefix events generated by this
         device, separated by a hyphen.
 
+        The gui argument can be set to True (as of Panda3D 1.10.3) to set up
+        the default MouseWatcher to receive inputs from this device, allowing
+        it to control user interfaces.
+
         If you call this, you should consider calling detachInputDevice when
         you are done with the device or when it is disconnected.
         """
@@ -1694,13 +1698,17 @@ class ShowBase(DirectObject.DirectObject):
         idn = self.dataRoot.attachNewNode(InputDeviceNode(device, device.name))
 
         # Setup the button thrower to generate events for the device.
-        bt = idn.attachNewNode(ButtonThrower(device.name))
-        if prefix is not None:
-            bt.node().setPrefix(prefix + '-')
+        if prefix is not None or not gui:
+            bt = idn.attachNewNode(ButtonThrower(device.name))
+            if prefix is not None:
+                bt.node().setPrefix(prefix + '-')
+            self.deviceButtonThrowers.append(bt)
 
         assert self.notify.debug("Attached input device {0} with prefix {1}".format(device, prefix))
         self.__inputDeviceNodes[device] = idn
-        self.deviceButtonThrowers.append(bt)
+
+        if gui:
+            idn.node().addChild(self.mouseWatcherNode)
 
     def detachInputDevice(self, device):
         """
diff --git a/panda/src/glstuff/glGraphicsStateGuardian_src.cxx b/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
index 6151a2c00d..3ad8e01428 100644
--- a/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
+++ b/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
@@ -597,8 +597,31 @@ reset() {
   query_glsl_version();
 
 #ifndef OPENGLES
-  bool core_profile = is_at_least_gl_version(3, 2) &&
-                      !has_extension("GL_ARB_compatibility");
+  // Determine whether this OpenGL context has compatibility features.
+  bool core_profile = false;
+
+  if (_gl_version_major >= 3) {
+    if (_gl_version_major > 3 || _gl_version_minor >= 2) {
+      // OpenGL 3.2 has a built-in way to check this.
+      GLint profile_mask = 0;
+      glGetIntegerv(GL_CONTEXT_PROFILE_MASK, &profile_mask);
+
+      if (profile_mask & GL_CONTEXT_CORE_PROFILE_BIT) {
+        core_profile = true;
+      } else if (profile_mask & GL_CONTEXT_COMPATIBILITY_PROFILE_BIT) {
+        core_profile = false;
+      } else {
+        core_profile = !has_extension("GL_ARB_compatibility");
+      }
+    } else {
+      // OpenGL 3.0/3.1.
+      GLint flags = 0;
+      glGetIntegerv(GL_CONTEXT_FLAGS, &flags);
+      if (flags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT) {
+        core_profile = true;
+      }
+    }
+  }
 
   if (GLCAT.is_debug()) {
     if (core_profile) {
diff --git a/panda/src/glstuff/glShaderContext_src.cxx b/panda/src/glstuff/glShaderContext_src.cxx
index 8789f26650..14264e142a 100644
--- a/panda/src/glstuff/glShaderContext_src.cxx
+++ b/panda/src/glstuff/glShaderContext_src.cxx
@@ -3206,6 +3206,10 @@ glsl_compile_and_link() {
     valid &= glsl_compile_shader(Shader::ST_compute);
   }
 
+  if (!valid) {
+    return false;
+  }
+
   // There might be warnings, so report those.  GLSLShaders::const_iterator
   // it; for (it = _glsl_shaders.begin(); it != _glsl_shaders.end(); ++it) {
   // glsl_report_shader_errors(*it); }
diff --git a/panda/src/glstuff/glmisc_src.cxx b/panda/src/glstuff/glmisc_src.cxx
index 08e200a4a0..49eaf78a69 100644
--- a/panda/src/glstuff/glmisc_src.cxx
+++ b/panda/src/glstuff/glmisc_src.cxx
@@ -17,6 +17,11 @@ ConfigVariableInt gl_version
   ("gl-version", "",
    PRC_DESC("Set this to get an OpenGL context with a specific version."));
 
+ConfigVariableBool gl_forward_compatible
+  ("gl-forward-compatible", false,
+   PRC_DESC("Setting this to true will request a forward-compatible OpenGL "
+            "context, which will not support the fixed-function pipeline."));
+
 ConfigVariableBool gl_support_fbo
   ("gl-support-fbo", true,
    PRC_DESC("Configure this false if your GL's implementation of "
diff --git a/panda/src/glstuff/glmisc_src.h b/panda/src/glstuff/glmisc_src.h
index 3c6dd81e7b..415286c674 100644
--- a/panda/src/glstuff/glmisc_src.h
+++ b/panda/src/glstuff/glmisc_src.h
@@ -41,6 +41,7 @@
 // #define GSG_VERBOSE 1
 
 extern EXPCL_GL ConfigVariableInt gl_version;
+extern EXPCL_GL ConfigVariableBool gl_forward_compatible;
 extern EXPCL_GL ConfigVariableBool gl_support_fbo;
 extern ConfigVariableBool gl_cheap_textures;
 extern ConfigVariableBool gl_ignore_clamp;
diff --git a/panda/src/glxdisplay/glxGraphicsStateGuardian.cxx b/panda/src/glxdisplay/glxGraphicsStateGuardian.cxx
index d620427afa..83ea5f2b2f 100644
--- a/panda/src/glxdisplay/glxGraphicsStateGuardian.cxx
+++ b/panda/src/glxdisplay/glxGraphicsStateGuardian.cxx
@@ -352,9 +352,20 @@ choose_pixel_format(const FrameBufferProperties &properties,
           attrib_list[n++] = gl_version[1];
         }
       }
+      int flags = 0;
       if (gl_debug) {
+        flags |= GLX_CONTEXT_DEBUG_BIT_ARB;
+      }
+      if (gl_forward_compatible) {
+        flags |= GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
+        if (gl_version.get_num_words() == 0 || gl_version[0] < 2) {
+          glxdisplay_cat.error()
+            << "gl-forward-compatible requires gl-version >= 3 0\n";
+        }
+      }
+      if (flags != 0) {
         attrib_list[n++] = GLX_CONTEXT_FLAGS_ARB;
-        attrib_list[n++] = GLX_CONTEXT_DEBUG_BIT_ARB;
+        attrib_list[n++] = flags;
       }
       attrib_list[n] = None;
       _context = _glXCreateContextAttribs(_display, _fbconfig, _share_context,
diff --git a/panda/src/pgui/pgButton.cxx b/panda/src/pgui/pgButton.cxx
index d1eba186c0..09a91120d4 100644
--- a/panda/src/pgui/pgButton.cxx
+++ b/panda/src/pgui/pgButton.cxx
@@ -115,7 +115,11 @@ release(const MouseWatcherParameter &param, bool background) {
   if (has_click_button(param.get_button())) {
     _button_down = false;
     if (get_active()) {
-      if (param.is_outside()) {
+      // Note that a "click" may come from a keyboard button press.  In that
+      // case, instead of checking that the mouse cursor is still over the
+      // button, we check whether the item has keyboard focus.
+      if (param.is_outside() &&
+          (MouseButton::is_mouse_button(param.get_button()) || !get_focus())) {
         set_state(S_ready);
       } else {
         set_state(S_rollover);
diff --git a/panda/src/wgldisplay/wglGraphicsStateGuardian.cxx b/panda/src/wgldisplay/wglGraphicsStateGuardian.cxx
index c98f12cf48..ed9b0e0b2c 100644
--- a/panda/src/wgldisplay/wglGraphicsStateGuardian.cxx
+++ b/panda/src/wgldisplay/wglGraphicsStateGuardian.cxx
@@ -609,9 +609,20 @@ make_context(HDC hdc) {
         attrib_list[n++] = gl_version[1];
       }
     }
+    int flags = 0;
     if (gl_debug) {
+      flags |= WGL_CONTEXT_DEBUG_BIT_ARB;
+    }
+    if (gl_forward_compatible) {
+      flags |= WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
+      if (gl_version.get_num_words() == 0 || gl_version[0] < 2) {
+        wgldisplay_cat.error()
+          << "gl-forward-compatible requires gl-version >= 3 0\n";
+      }
+    }
+    if (flags != 0) {
       attrib_list[n++] = WGL_CONTEXT_FLAGS_ARB;
-      attrib_list[n++] = WGL_CONTEXT_DEBUG_BIT_ARB;
+      attrib_list[n++] = flags;
     }
 #ifndef SUPPORT_FIXED_FUNCTION
     attrib_list[n++] = WGL_CONTEXT_PROFILE_MASK_ARB;
diff --git a/panda/src/windisplay/config_windisplay.cxx b/panda/src/windisplay/config_windisplay.cxx
index 6e0ea2406d..62040c553a 100644
--- a/panda/src/windisplay/config_windisplay.cxx
+++ b/panda/src/windisplay/config_windisplay.cxx
@@ -86,6 +86,11 @@ ConfigVariableBool swapbuffer_framelock
 ("swapbuffer-framelock", false,
  PRC_DESC("Set this true to enable HW swapbuffer frame-lock on 3dlabs cards"));
 
+ConfigVariableBool paste_emit_keystrokes
+("paste-emit-keystrokes", true,
+ PRC_DESC("Handle paste events (Ctrl-V) as separate keystroke events for each "
+          "pasted character."));
+
 /**
  * Initializes the library.  This must be called at least once before any of
  * the functions or classes in this library can be used.  Normally it will be
diff --git a/panda/src/windisplay/config_windisplay.h b/panda/src/windisplay/config_windisplay.h
index 3256287f5b..7199b8603d 100644
--- a/panda/src/windisplay/config_windisplay.h
+++ b/panda/src/windisplay/config_windisplay.h
@@ -31,6 +31,7 @@ extern ConfigVariableBool ime_hide;
 extern ConfigVariableBool request_dxdisplay_information;
 extern ConfigVariableBool dpi_aware;
 extern ConfigVariableBool dpi_window_resize;
+extern ConfigVariableBool paste_emit_keystrokes;
 
 extern EXPCL_PANDAWIN ConfigVariableBool swapbuffer_framelock;
 
diff --git a/panda/src/windisplay/winGraphicsWindow.cxx b/panda/src/windisplay/winGraphicsWindow.cxx
index d3e444cac9..c2e98beb0e 100644
--- a/panda/src/windisplay/winGraphicsWindow.cxx
+++ b/panda/src/windisplay/winGraphicsWindow.cxx
@@ -1927,7 +1927,7 @@ window_proc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) {
       // Handle Cntrl-V paste from clipboard.  Is there a better way to detect
       // this hotkey?
       if ((wparam=='V') && (GetKeyState(VK_CONTROL) < 0) &&
-          !_input_devices.empty()) {
+          !_input_devices.empty() && paste_emit_keystrokes) {
         HGLOBAL hglb;
         char *lptstr;