add -C[NUM] to git-am

Add -C[NUM] to git-am and git-rebase so that patches can be applied even
if context has changed a bit.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-am.txt

@@ -64,6 +64,10 @@ default.   You could use `--no-utf8` to override this.
 	This flag is passed to the `git-apply` program that applies
 	the patch.
 
+-C<n>::
+	This flag is passed to the `git-apply` program that applies
+	the patch.
+
 --interactive::
 	Run interactively, just like git-applymbox.
 

Documentation/git-rebase.txt

@@ -7,7 +7,7 @@ git-rebase - Forward-port local commits to the updated upstream head
 
 SYNOPSIS
 --------
-'git-rebase' [-v] [--merge] [--onto <newbase>] <upstream> [<branch>]
+'git-rebase' [-v] [--merge] [-CNUM] [--onto <newbase>] <upstream> [<branch>]
 
 'git-rebase' --continue | --skip | --abort
 
@@ -196,6 +196,12 @@ OPTIONS
 -v, \--verbose::
 	Display a diffstat of what changed upstream since the last rebase.
 
+-C<n>::
+	Ensure at least <n> lines of surrounding context match before
+	and after each change.  When fewer lines of surrounding
+	context exist they all must match.  By default no context is
+	ever ignored.
+
 include::merge-strategies.txt[]
 
 NOTES

git-am.sh

@@ -3,7 +3,7 @@
 # Copyright (c) 2005, 2006 Junio C Hamano
 
 USAGE='[--signoff] [--dotest=<dir>] [--utf8 | --no-utf8] [--binary] [--3way]
-  [--interactive] [--whitespace=<option>] <mbox>...
+  [--interactive] [--whitespace=<option>] [-CNUM] <mbox>...
   or, when resuming [--skip | --resolved]'
 . git-sh-setup
 set_reflog_action am
@@ -106,7 +106,8 @@ It does not apply to blobs recorded in its index."
 }
 
 prec=4
-dotest=.dotest sign= utf8=t keep= skip= interactive= resolved= binary= ws= resolvemsg=
+dotest=.dotest sign= utf8=t keep= skip= interactive= resolved= binary= resolvemsg=
+git_apply_opt=
 
 while case "$#" in 0) break;; esac
 do
@@ -142,7 +143,10 @@ do
 	skip=t; shift ;;
 
 	--whitespace=*)
-	ws=$1; shift ;;
+	git_apply_opt="$git_apply_opt $1"; shift ;;
+
+	-C*)
+	git_apply_opt="$git_apply_opt $1"; shift ;;
 
 	--resolvemsg=*)
 	resolvemsg=$(echo "$1" | sed -e "s/^--resolvemsg=//"); shift ;;
@@ -394,7 +398,7 @@ do
 
 	case "$resolved" in
 	'')
-		git-apply $binary --index $ws "$dotest/patch"
+		git-apply $git_apply_opt $binary --index "$dotest/patch"
 		apply_status=$?
 		;;
 	t)

git-rebase.sh

@@ -45,6 +45,7 @@ do_merge=
 dotest=$GIT_DIR/.dotest-merge
 prec=4
 verbose=
+git_am_opt=
 
 continue_merge () {
 	test -n "$prev_head" || die "prev_head must be defined"
@@ -213,6 +214,10 @@ do
 	-v|--verbose)
 		verbose=t
 		;;
+	-C*)
+		git_am_opt=$1
+		shift
+		;;
 	-*)
 		usage
 		;;
@@ -322,7 +327,7 @@ fi
 if test -z "$do_merge"
 then
 	git-format-patch -k --stdout --full-index --ignore-if-in-upstream "$upstream"..ORIG_HEAD |
-	git am --binary -3 -k --resolvemsg="$RESOLVEMSG"
+	git am $git_am_opt --binary -3 -k --resolvemsg="$RESOLVEMSG"
 	exit $?
 fi