I compiled mozilla trunk on 8/20/2002 with the gtk patch included in galeon cvs with the following configure flags:

/configure \
--prefix=/usr/local/gnome2 \
--with-pthreads \
--enable-default-toolkit=gtk2 \
--disable-mailnews \
--disable-ldap \
--disable-postscript \
--disable-xprint \
--enable-crypto \
--disable-jsd \
--disable-bidi \
--disable-accessibility \
--disable-installer \
--disable-tests \
--disable-debug \
--enable-optimize="-O2 -march=athlon -mcpu=athlon" \
--disable-dtd-debug \
--disable-logging \
--enable-strip

and this is the resulting error on gcc-2.96


gcc -o keysym2ucs.o -c -DOSTYPE=\"Linux2.4\" -DOSARCH=\"Linux\" -DOJI  -I../../../dist/include/xpcom -I../../../dist/include/string -I../../../dist/include/gfx -I../../../dist/include/pref -I../../../dist/include/dom -I../../../dist/include/accessibility -I../../../dist/include/xremoteservice -I../../../dist/include/widget -I../../../dist/include -I/usr/local/gnome2-build/cvs/mozilla/dist/include/nspr      -I./../xpwidgets  -I/usr/X11R6/include   -fPIC -I/usr/X11R6/include -Wall -W -Wno-unused -Wpointer-arith -Wcast-align -pedantic -Wno-long-long -pthread -pipe  -DNDEBUG -DTRIMMED -O2 -march=athlon -mcpu=athlon -I/usr/local/gnome2/include/gtk-2.0 -I/usr/local/gnome2/lib/gtk-2.0/include -I/usr/local/gnome2/include/atk-1.0 -I/usr/local/gnome2/include/pango-1.0 -I/usr/X11R6/include -I/usr/include/freetype2 -I/usr/local/gnome2/include/glib-2.0 -I/usr/local/gnome2/lib/glib-2.0/include    -I/usr/X11R6/include -include ../../../config-defs.h -DMOZILLA_CLIENT -Wp,-MD,.deps/keysym2ucs.pp keysym2ucs.c
nsWindow.cpp
c++ -o nsWindow.o -c -DOSTYPE=\"Linux2.4\" -DOSARCH=\"Linux\" -DOJI  -I../../../dist/include/xpcom -I../../../dist/include/string -I../../../dist/include/gfx -I../../../dist/include/pref -I../../../dist/include/dom -I../../../dist/include/accessibility -I../../../dist/include/xremoteservice -I../../../dist/include/widget -I../../../dist/include -I/usr/local/gnome2-build/cvs/mozilla/dist/include/nspr      -I./../xpwidgets  -I/usr/X11R6/include   -fPIC  -I/usr/X11R6/include -fno-rtti -fno-exceptions -Wall -Wconversion -Wpointer-arith -Wbad-function-cast -Wcast-align -Woverloaded-virtual -Wsynth -Wno-ctor-dtor-privacy -pedantic -Wno-long-long -fshort-wchar -pthread -pipe  -DNDEBUG -DTRIMMED -O2 -march=athlon -mcpu=athlon -I/usr/local/gnome2/include/gtk-2.0 -I/usr/local/gnome2/lib/gtk-2.0/include -I/usr/local/gnome2/include/atk-1.0 -I/usr/local/gnome2/include/pango-1.0 -I/usr/X11R6/include -I/usr/include/freetype2 -I/usr/local/gnome2/include/glib-2.0 -I/usr/local/gnome2/lib/glib-2.0/include    -I/usr/X11R6/include -DMOZILLA_CLIENT -include ../../../config-defs.h -Wp,-MD,.deps/nsWindow.pp nsWindow.cpp
nsWindow.cpp: In method `nsWindow::~nsWindow ()':
nsWindow.cpp:211: `gWidgetLog' undeclared (first use this function)
nsWindow.cpp:211: (Each undeclared identifier is reported only once for 
each function it appears in.)
nsWindow.cpp:211: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:211: `PR_LOG' undeclared (first use this function)
nsWindow.cpp: In method `nsresult nsWindow::Destroy ()':
nsWindow.cpp:261: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::SetModal (int)':
nsWindow.cpp:337: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:337: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::Move (int, int)':
nsWindow.cpp:397: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:397: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:397: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::SetSizeMode (int)':
nsWindow.cpp:434: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:434: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::SetFocus (int)':
nsWindow.cpp:478: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:525: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::GetScreenBounds (nsRect 
&)':
nsWindow.cpp:550: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:550: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:550: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:550: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:550: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:550: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::Invalidate (int)':
nsWindow.cpp:633: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:633: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:633: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:633: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:633: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::Invalidate (const nsRect &, 
int)':
nsWindow.cpp:655: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:655: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:655: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:655: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:655: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::InvalidateRegion (const 
nsIRegion *, int)':
nsWindow.cpp:677: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:677: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:677: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:677: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:677: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:684: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::SetIcon (const nsAString 
&)':
nsWindow.cpp:841: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::WidgetToScreen (const 
nsRect &, nsRect &)':
nsWindow.cpp:872: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:872: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:876: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp:876: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::CaptureMouse (int)':
nsWindow.cpp:931: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::CaptureRollupEvents 
(nsIRollupListener *, int, int)':
nsWindow.cpp:956: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `nsresult nsWindow::GetAttention ()':
nsWindow.cpp:980: warning: left-hand operand of comma expression has no 
effect
nsWindow.cpp: In method `gboolean nsWindow::OnExposeEvent (GtkWidget *, 
GdkEventExpose *)':
nsWindow.cpp:1009: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1009: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1018: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1018: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1018: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1018: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1018: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1018: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `gboolean nsWindow::OnConfigureEvent (GtkWidget 
*, GdkEventConfigure *)':
nsWindow.cpp:1053: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1053: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1053: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1053: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1053: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::OnSizeAllocate (GtkWidget *, 
GtkAllocation *)':
nsWindow.cpp:1078: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1078: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1078: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1078: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1078: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::OnEnterNotifyEvent (GtkWidget 
*, GdkEventCrossing *)':
nsWindow.cpp:1117: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::OnLeaveNotifyEvent (GtkWidget 
*, GdkEventCrossing *)':
nsWindow.cpp:1132: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::OnWindowStateEvent (GtkWidget 
*, GdkEventWindowState *)':
nsWindow.cpp:1398: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1398: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1398: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::OnDragLeaveEvent (GtkWidget *, 
GdkDragContext *, unsigned int, void *)':
nsWindow.cpp:1530: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::OnDragDataReceivedEvent 
(GtkWidget *, GdkDragContext *, int, int, GtkSelectionData *, unsigned 
int, unsigned int, void *)':
nsWindow.cpp:1666: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::OnDragLeave ()':
nsWindow.cpp:1679: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::OnDragEnter (int, int)':
nsWindow.cpp:1702: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `nsresult nsWindow::NativeCreate (nsIWidget *, 
void *, const nsRect &, nsEventStatus (*) (nsGUIEvent *), 
nsIDeviceContext *, nsIAppShell *, nsIToolkit *, nsWidgetInitData *)':
nsWindow.cpp:1758: warning: ISO C++ forbids braced-groups within 
expressions
nsWindow.cpp:1760: warning: ISO C++ forbids braced-groups within 
expressions
nsWindow.cpp:1818: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1818: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1841: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1841: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1957: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1959: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1959: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1959: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1964: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1964: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1970: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1970: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1970: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1970: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::NativeResize (int, int, int)':
nsWindow.cpp:1986: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1986: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:1986: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::NativeResize (int, int, int, 
int, int)':
nsWindow.cpp:2014: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:2014: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:2014: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:2014: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:2014: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::GrabPointer ()':
nsWindow.cpp:2092: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::GrabKeyboard ()':
nsWindow.cpp:2125: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp:2154: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In function `PRBool is_mouse_in_window (GdkWindow *, 
double, double)':
nsWindow.cpp:2273: warning: ISO C++ forbids braced-groups within 
expressions
nsWindow.cpp: In function `nsresult initialize_default_icon ()':
nsWindow.cpp:2890: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::FireDragMotionTimer ()':
nsWindow.cpp:2952: warning: left-hand operand of comma expression has 
no effect
nsWindow.cpp: In method `void nsWindow::FireDragLeaveTimer ()':
nsWindow.cpp:2962: warning: left-hand operand of comma expression has 
no effect
make[4]: *** [nsWindow.o] Error 1
make[4]: Leaving directory `/usr/local/gnome2-build/cvs/mozilla/widget/src/gtk2'make[3]: *** [libs] Error 2
make[3]: Leaving directory `/usr/local/gnome2-build/cvs/mozilla/widget/src'
make[2]: *** [libs] Error 2
make[2]: Leaving directory `/usr/local/gnome2-build/cvs/mozilla/widget'
make[1]: *** [tier_9] Error 2
make[1]: Leaving directory `/usr/local/gnome2-build/cvs/mozilla'
make: *** [default] Error 2
[aldug@edison mozilla]$