[PATCH] merge_config.sh: Use the first file as the initial config

[Josh Boyer <jwboyer@redhat.com>]

Take the first config fragment and use it verbatim as the initial config set.
This avoids running the verification loop for the first file, as nothing has
actually been merged at this point.  This significantly increases performance
for large config fragments.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
---

When experimenting with merge_config.sh on the Fedora config fragments, this
cut the execution time of a single invocation with all the config fragments
in half (from 28 seconds to 13 seconds).

 scripts/kconfig/merge_config.sh |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/scripts/kconfig/merge_config.sh b/scripts/kconfig/merge_config.sh
index ceadf0e..23d738a 100644
--- a/scripts/kconfig/merge_config.sh
+++ b/scripts/kconfig/merge_config.sh
@@ -58,12 +58,16 @@ while true; do
 	esac
 done
 
-
+INITFILE=$1
+shift;
 
 MERGE_LIST=$*
 SED_CONFIG_EXP="s/^\(# \)\{0,1\}\(CONFIG_[a-zA-Z0-9_]*\)[= ].*/\2/p"
 TMP_FILE=$(mktemp ./.tmp.config.XXXXXXXXXX)
 
+echo "Using $INITFILE as base"
+cat $INITFILE > $TMP_FILE
+
 # Merge files, printing warnings on overrided values
 for MERGE_FILE in $MERGE_LIST ; do
 	echo "Merging $MERGE_FILE"
-- 
1.7.8.4