Teach 'git pull' about --rebase

When calling 'git pull' with the '--rebase' option, it performs a
fetch + rebase instead of a fetch + merge.

This behavior is more desirable than fetch + pull when a topic branch
is ready to be submitted and needs to be update.

fetch + rebase might also be considered a better workflow with shared
repositories in any case, or for contributors to a centrally managed
repository, such as WINE's.

As a convenience, you can set the default behavior for a branch by
defining the config variable branch.<name>.rebase, which is
interpreted as a bool.  This setting can be overridden on the command
line by --rebase and --no-rebase.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-pull.sh

@@ -17,6 +17,9 @@ test -z "$(git ls-files -u)" ||
 	die "You are in the middle of a conflicted merge."
 
 strategy_args= no_summary= no_commit= squash= no_ff=
+curr_branch=$(git symbolic-ref -q HEAD)
+curr_branch_short=$(echo "$curr_branch" | sed "s|refs/heads/||")
+rebase=$(git config --bool branch.$curr_branch_short.rebase)
 while :
 do
 	case "$1" in
@@ -52,6 +55,12 @@ do
 		esac
 		strategy_args="${strategy_args}-s $strategy "
 		;;
+	-r|--r|--re|--reb|--reba|--rebas|--rebase)
+		rebase=true
+		;;
+	--no-r|--no-re|--no-reb|--no-reba|--no-rebas|--no-rebase)
+		rebase=false
+		;;
 	-h|--h|--he|--hel|--help)
 		usage
 		;;
@@ -95,7 +104,6 @@ merge_head=$(sed -e '/	not-for-merge	/d' \
 
 case "$merge_head" in
 '')
-	curr_branch=$(git symbolic-ref -q HEAD)
 	case $? in
 	  0) ;;
 	  1) echo >&2 "You are not currently on a branch; you must explicitly"
@@ -142,5 +150,6 @@ then
 fi
 
 merge_name=$(git fmt-merge-msg <"$GIT_DIR/FETCH_HEAD") || exit
+test true = "$rebase" && exec git-rebase $merge_head
 exec git-merge $no_summary $no_commit $squash $no_ff $strategy_args \
 	"$merge_name" HEAD $merge_head