--- mozilla-firefox.SlackBuild	2012-07-17 22:51:41.000000000 +0200
+++ mozilla-firefox.SlackBuild.new	2012-12-30 09:49:50.423661000 +0100
@@ -25,21 +25,28 @@

 VERSION=$(basename $(ls firefox-*.tar.bz2 | cut -d - -f 2 | rev | cut -f 3- -d . | rev) .source)
 RELEASEVER=$(echo $VERSION | cut -f 1 -d r | cut -f 1 -d b)
+# With esr releases we need to fix this
+if [ "${RELEASEVER}r" = "$VERSION" ]; then
+  RELEASEVER=$(echo $RELEASEVER | cut -f 1 -d e)
+  RELEASEVERMAJ=$(echo $RELEASEVER | cut -f 1 -d .)
+fi
 BUILD=${BUILD:-1}

 CWD=$(pwd)
 TMP=${TMP:-/tmp}
 PKG=$TMP/package-mozilla-firefox

-# Figure out if this is a beta, or a release:
+# If not specified, figure out if this is a beta, an esr
+# or a release (we start assuming this last):
+MOZVERS=${MOZVERS:-release}
 if echo $VERSION | grep -q b ; then # we think it is a beta
-  if bzgrep -q mozilla-beta/ $CWD/firefox-$VERSION.source.tar.bz2 ; then
-    MOZVERS=${MOZVERS:-beta}
-  else # blindly assume it is a release
-    MOZVERS=${MOZVERS:-release}
+  if bzgrep -q ^mozilla-beta/ $CWD/firefox-$VERSION.source.tar.bz2 ; then
+    MOZVERS=beta
+  fi
+elif echo $VERSION | grep -q esr ; then # we think it is an esr
+  if bzgrep -q ^mozilla-esr$RELEASEVERMAJ/ $CWD/firefox-$VERSION.source.tar.bz2 ; then
+    MOZVERS=esr$RELEASEVERMAJ
   fi
-else # release, no "b" in the tarball version:
-  MOZVERS=${MOZVERS:-release}
 fi

 # Automatically determine the architecture we're building on:
@@ -111,18 +118,8 @@
  sed -i 's# ""##' browser/base/Makefile.in
 fi

-# Mozilla devs enforce using an objdir for building
-# and launching configure with the absolute path
-# https://developer.mozilla.org/en/Configuring_Build_Options#Building_with_an_objdir
-mkdir obj
-cd obj
-export MOZILLA_OFFICIAL="1" &&
-export BUILD_OFFICIAL="1" &&
-export MOZ_PHOENIX="1" &&
-export CFLAGS="$SLKCFLAGS" &&
-export CXXFLAGS="$SLKCFLAGS" &&
-export MOZ_MAKE_FLAGS="$NUMJOBS" &&
-$TMP/mozilla-$MOZVERS/configure \
+# Our building options, in a configure-like display ;)
+OPTIONS="\
   --enable-official-branding \
   --prefix=/usr \
   --libdir=/usr/lib${LIBDIRSUFFIX} \
@@ -143,6 +140,7 @@
   --enable-strip \
   --enable-cpp-rtti \
   --enable-single-profile \
+  --disable-gnomevfs \
   --disable-ldap \
   --disable-accessibility \
   --disable-crashreporter \
@@ -152,20 +150,53 @@
   --disable-installer \
   --disable-mailnews \
   --disable-composer \
-  --disable-profilesharing
-  # Complains about missing APNG support in Slackware's libpng:
-  #--with-system-png \
-
+  --disable-profilesharing"
+# Complains about missing APNG support in Slackware's libpng:
+# --with-system-png \
 # This option breaks mozilla-12.0:
 # --enable-system-cairo \
-#

-#make -f client.mk build MOZ_MAKE_FLAGS="$NUMJOBS" || exit 1
-make MOZ_MAKE_FLAGS="$NUMJOBS" $NUMJOBS || exit 1
-make install DESTDIR=$PKG || exit 1
+export MOZILLA_OFFICIAL="1"
+export BUILD_OFFICIAL="1"
+export MOZ_PHOENIX="1"
+export CFLAGS="$SLKCFLAGS"
+export CXXFLAGS="$SLKCFLAGS"
+export MOZ_MAKE_FLAGS="$NUMJOBS"
+
+# Clear some variables that could break the build
+unset DBUS_SESSION_BUS_ADDRESS ORBIT_SOCKETDIR SESSION_MANAGER \
+  XDG_SESSION_COOKIE XAUTHORITY MAKEFLAGS
+
+# Assemble our .mozconfig, we use this method for building, seems
+# needed for PGO.
+echo ". \$topsrcdir/browser/config/mozconfig" > .mozconfig
+
+# Mozilla devs enforce using an objdir for building
+# https://developer.mozilla.org/en/Configuring_Build_Options#Building_with_an_objdir
+mkdir obj
+echo "mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/obj" >> .mozconfig
+
+# Write in it the options above
+for option in $OPTIONS; do echo "ac_add_options $option" >> .mozconfig; done
+
+# https://developer.mozilla.org/en-US/docs/Building_with_Profile-Guided_Optimization
+# Thanks to ArchLinux and Gentoo for the additional hints.
+if [ "${PGO:-no}" = "yes" ]; then
+  # Do a PGO build, double time and disk space but worth it.
+  export MOZ_PGO=1
+  echo "mk_add_options PROFILE_GEN_SCRIPT='\$(PYTHON) \$(MOZ_OBJDIR)/_profile/pgo/profileserver.py 10'" >> .mozconfig
+  export DISPLAY=:99
+  # Launch Xvfb to let the profile scripts run in a X session.
+  # Ugly note: if the build breaks you may want to do a "killall Xvfb".
+  Xvfb -nolisten tcp -extension GLX -screen 0 1280x1024x24 $DISPLAY &
+  dbus-launch --exit-with-session make -f client.mk build
+  kill $! || true
+else
+  # Do a normal build
+  make -f client.mk build
+fi

-# Exit obj directory:
-cd ..
+make -f client.mk install DESTDIR=$PKG

 # We don't need these (just symlinks anyway):
 rm -rf $PKG/usr/lib${LIBDIRSUFFIX}/firefox-devel-$RELEASEVER