--- a/configure.in	Mon Aug 13 11:00:13 2007 +0200
+++ b/configure.in	Mon Aug 13 11:01:07 2007 +0200
@@ -2333,7 +2333,9 @@
   done
 
   dnl Avoid version mismatch for shared library libXm.so on osf4
-  if test "$GCC" = yes -a -d /usr/shlib; then XE_APPEND(-L/usr/shlib, X_LIBS); fi
+  case "$opsys" in
+  decosf*) if test "$GCC" = yes -a -d /usr/shlib; then XE_APPEND(-L/usr/shlib, X_LIBS); fi ;;
+  esac
 
   ld_switch_x_site="$X_LIBS"
 
@@ -2558,6 +2560,14 @@
   done
 fi
 
+dnl Balloon Help requires the Shape extension, not available everywhere,
+dnl for example not on AIX 4.3.
+if test "$with_x11" = "yes"; then
+  AC_CHECK_HEADER(X11/extensions/shape.h, [
+   AC_DEFINE(HAVE_BALLOON_HELP)
+   XE_ADD_OBJS(balloon_help.o balloon-x.o)])
+fi
+
 dnl FSF 19.29 has some bitmapdir stuff here.
 bitmapdir=
 
@@ -3236,8 +3246,11 @@
 dnl  AC_CHECK_FUNC(alloca, [:], [AC_CHECK_LIB(PW, alloca)])
 dnl esac
 
+dnl AC_FUNC_ALLOCA doesn't know about DEC C's #pragma intrinsic(alloca)
+if test "$__DECC" != "yes"; then
 AC_FUNC_ALLOCA
 test -n "$ALLOCA" && XE_ADD_OBJS($ALLOCA)
+fi
 
 dnl Check whether vfork exists and works correctly. (This does more
 dnl than just check for its existence.) If so, it defines HAVE_VFORK_H.
@@ -3435,7 +3448,7 @@
   XE_ADD_OBJS(nas.o)
   XE_PREPEND(-laudio, libs_x)
   dnl If the nas library does not contain the error jump point,
-  dnl then we force safer behaviour.
+  dnl then we force safer behavior.
   AC_EGREP_HEADER(AuXtErrorJump,audio/Xtutil.h,,[AC_DEFINE(NAS_NO_ERROR_JUMP)])
   dnl NAS <= 1.2p5 defines {BIG,LITTLE}_ENDIAN in conflict with GNU libc etc
   dnl Recent NAS prefixes NAS_ to avoid polluting namespace