--- a/client.mk
+++ b/client.mk
@@ -257,17 +257,16 @@ EXTRA_CONFIG_DEPS := \
 	cd $(@D); $(AUTOCONF)
 
 CONFIG_STATUS_DEPS := \
 	$(wildcard $(CONFIGURES)) \
 	$(TOPSRCDIR)/allmakefiles.sh \
 	$(TOPSRCDIR)/.mozconfig.mk \
 	$(TOPSRCDIR)/mozilla/allmakefiles.sh \
 	$(wildcard $(TOPSRCDIR)/mozilla/nsprpub/configure) \
-	$(wildcard $(TOPSRCDIR)/mozilla/js/src/configure) \
 	$(wildcard $(TOPSRCDIR)/mozilla/config/milestone.txt) \
 	$(wildcard $(TOPSRCDIR)/directory/c-sdk/configure) \
 	$(wildcard $(addsuffix confvars.sh,$(wildcard $(TOPSRCDIR)/*/))) \
 	$(NULL)
 
 # configure uses the program name to determine @srcdir@. Calling it without
 #   $(TOPSRCDIR) will set @srcdir@ to "."; otherwise, it is set to the full
 #   path of $(TOPSRCDIR).

--- a/config/rules.mk
+++ b/config/rules.mk
@@ -389,18 +389,20 @@ ifndef PROGOBJS
 PROGOBJS		= $(OBJS)
 endif
 
 ifndef HOST_PROGOBJS
 HOST_PROGOBJS		= $(HOST_OBJS)
 endif
 
 # MAKE_DIRS: List of directories to build while looping over directories.
-ifneq (,$(OBJS)$(XPIDLSRCS)$(SDK_XPIDLSRCS)$(SIMPLE_PROGRAMS))
-MAKE_DIRS		+= $(MDDEPDIR)
+# A Makefile that needs $(MDDEPDIR) created but doesn't set any of these
+# variables we know to check can just set NEED_MDDEPDIR explicitly.
+ifneq (,$(OBJS)$(XPIDLSRCS)$(SDK_XPIDLSRCS)$(SIMPLE_PROGRAMS)$(NEED_MDDEPDIR))
+MAKE_DIRS		+= $(CURDIR)/$(MDDEPDIR)
 GARBAGE_DIRS		+= $(MDDEPDIR)
 endif
 
 #
 # Tags: emacs (etags), vi (ctags)
 # TAG_PROGRAM := ctags -L -
 #
 TAG_PROGRAM		= xargs etags -a
@@ -1918,17 +1920,23 @@ endif # COMPILER_DEPEND
 
 
 #############################################################################
 # MDDEPDIR is the subdirectory where all the dependency files are placed.
 #   This uses a make rule (instead of a macro) to support parallel
 #   builds (-jN). If this were done in the LOOP_OVER_DIRS macro, two
 #   processes could simultaneously try to create the same directory.
 #
-$(MDDEPDIR):
+#   We use $(CURDIR) in the rule's target to ensure that we don't find
+#   a dependency directory in the source tree via VPATH (perhaps from
+#   a previous build in the source tree) and thus neglect to create a
+#   dependency directory in the object directory, where we really need
+#   it.
+
+$(CURDIR)/$(MDDEPDIR):
 	@if test ! -d $@; then echo Creating $@; rm -rf $@; mkdir $@; else true; fi
 
 ifneq (,$(filter-out all chrome default export realchrome tools clean clobber clobber_all distclean realclean,$(MAKECMDGOALS)))
 ifneq (,$(OBJS)$(XPIDLSRCS)$(SDK_XPIDLSRCS)$(SIMPLE_PROGRAMS))
 MDDEPEND_FILES		:= $(strip $(wildcard $(MDDEPDIR)/*.pp))
 
 ifneq (,$(MDDEPEND_FILES))
 ifdef PERL

--- a/configure.in
+++ b/configure.in
@@ -687,17 +687,16 @@ if test "$_perl_res" != 0; then
 else
     AC_MSG_RESULT([yes])    
 fi
 
 AC_PATH_PROGS(PYTHON, $PYTHON python)
 if test -z "$PYTHON"; then
     AC_MSG_ERROR([python was not found in \$PATH])
 fi
-echo PYTHON="$PYTHON"
 
 AC_PATH_PROGS(NSINSTALL_BIN, nsinstall )
 if test -z "$COMPILE_ENVIRONMENT"; then
 if test -z "$NSINSTALL_BIN" || test "$NSINSTALL_BIN" = ":"; then
     NSINSTALL_BIN='$(PYTHON) $(MOZILLA_SRCDIR)/config/nsinstall.py'
 fi
 fi
 AC_SUBST(NSINSTALL_BIN)
@@ -1833,32 +1832,39 @@ case "$target" in
        MOZ_FIX_LINK_PATHS=
     fi
     if test -z "$GNU_CXX"; then
       MIPSPRO_CXX=1
     fi
     ;;
 
 *-*linux*)
-    if test "$GNU_CC"; then
+    # Note: both GNU_CC and INTEL_CC are set when using Intel's C compiler.
+    # Similarly for GNU_CXX and INTEL_CXX.
+    if test "$INTEL_CC" || test "$INTEL_CXX"; then
+        # -Os has been broken on Intel's C/C++ compilers for quite a
+        # while; Intel recommends against using it.
+        MOZ_OPTIMIZE_FLAGS="-O2"
+        MOZ_DEBUG_FLAGS="-g -fno-inline"
+    elif test "$GNU_CC" || test "$GNU_CXX"; then
         GCC_VERSION=`$CC -v 2>&1 | awk '/^gcc version/ { print $3 }'`
         case $GCC_VERSION in
         4.1.*|4.2.*)
             # -Os is broken on gcc 4.1.x and 4.2.x, we need to tweak it to get good results.
             MOZ_OPTIMIZE_SIZE_TWEAK="-finline-limit=50"
         esac
+        MOZ_OPTIMIZE_FLAGS="-Os -freorder-blocks -fno-reorder-functions $MOZ_OPTIMIZE_SIZE_TWEAK"
+        MOZ_DEBUG_FLAGS="-g -fno-inline"  # most people on linux use gcc/gdb,
+                                          # and that combo is not yet good at
+                                          # debugging inlined functions (even
+                                          # when using DWARF2 as the debugging
+                                          # format)
     fi
 
     TARGET_NSPR_MDCPUCFG='\"md/_linux.cfg\"'
-    MOZ_OPTIMIZE_FLAGS="-Os -freorder-blocks -fno-reorder-functions $MOZ_OPTIMIZE_SIZE_TWEAK"
-    MOZ_DEBUG_FLAGS="-g -fno-inline"  # most people on linux use gcc/gdb,
-                                      # and that combo is not yet good at
-                                      # debugging inlined functions (even
-                                      # when using DWARF2 as the debugging
-                                      # format)    
 
     MOZ_MEMORY=1
 
     case "${target_cpu}" in
     alpha*)
     	CFLAGS="$CFLAGS -mieee"
     	CXXFLAGS="$CXXFLAGS -mieee"
     ;;