diff -r 000000000000 -r 1918ee327afb mkspecs/features/mac/default_post.prf
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mkspecs/features/mac/default_post.prf	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,17 @@
+load(default_post)
+!no_objective_c:CONFIG += objective_c
+
+# Pick a suitable default architecture for qmake-based applications.
+# If the Qt package contains one of x86 and x86_64, pick that one. If it
+# contains both then use the compiler default. Make a similiar decision for
+# PowerPC-based systems. Note that this logic assumes that Qt has been 
+# configured with an architecture that is usable on the system.
+qt:!isEmpty(QT_CONFIG) {
+    contains(QMAKE_HOST.arch, ppc) {
+        !contains(QT_CONFIG, ppc64):contains(QT_CONFIG, ppc):CONFIG += ppc
+        contains(QT_CONFIG, ppc64):!contains(QT_CONFIG, ppc):CONFIG += ppc64
+    } else {
+        !contains(QT_CONFIG, x86_64):contains(QT_CONFIG, x86):CONFIG += x86
+        contains(QT_CONFIG, x86_64):!contains(QT_CONFIG, x86):CONFIG += x86_64
+    }
+}