Drop unused git-rebase--am.sh

Since 21853626ea (built-in rebase: call `git am` directly, 2019-01-18),
the built-in rebase already uses the built-in `git am` directly.

Now that d03ebd411c (rebase: remove the rebase.useBuiltin setting,
2019-03-18) even removed the scripted rebase, there is no longer any
user of `git-rebase--am.sh`, so let's just remove it.

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

.gitignore

@@ -122,7 +122,6 @@
 /git-range-diff
 /git-read-tree
 /git-rebase
-/git-rebase--am
 /git-rebase--common
 /git-rebase--interactive
 /git-rebase--preserve-merges

Makefile

@@ -624,7 +624,6 @@ SCRIPT_SH += git-web--browse.sh
 
 SCRIPT_LIB += git-mergetool--lib
 SCRIPT_LIB += git-parse-remote
-SCRIPT_LIB += git-rebase--am
 SCRIPT_LIB += git-rebase--common
 SCRIPT_LIB += git-rebase--preserve-merges
 SCRIPT_LIB += git-sh-setup

builtin/rebase.c

@@ -1153,10 +1153,6 @@ static int run_specific_rebase(struct rebase_options *opts, enum action action)
 	}
 
 	switch (opts->type) {
-	case REBASE_AM:
-		backend = "git-rebase--am";
-		backend_func = "git_rebase__am";
-		break;
 	case REBASE_PRESERVE_MERGES:
 		backend = "git-rebase--preserve-merges";
 		backend_func = "git_rebase__preserve_merges";

git-rebase--am.sh

@@ -1,85 +0,0 @@
-# This shell script fragment is sourced by git-rebase to implement
-# its default, fast, patch-based, non-interactive mode.
-#
-# Copyright (c) 2010 Junio C Hamano.
-#
-
-git_rebase__am () {
-
-case "$action" in
-continue)
-	git am --resolved --resolvemsg="$resolvemsg" \
-		${gpg_sign_opt:+"$gpg_sign_opt"} &&
-	move_to_original_branch
-	return
-	;;
-skip)
-	git am --skip --resolvemsg="$resolvemsg" &&
-	move_to_original_branch
-	return
-	;;
-show-current-patch)
-	exec git am --show-current-patch
-	;;
-esac
-
-if test -z "$rebase_root"
-	# this is now equivalent to ! -z "$upstream"
-then
-	revisions=$upstream...$orig_head
-else
-	revisions=$onto...$orig_head
-fi
-
-ret=0
-rm -f "$GIT_DIR/rebased-patches"
-
-git format-patch -k --stdout --full-index --cherry-pick --right-only \
-	--src-prefix=a/ --dst-prefix=b/ --no-renames --no-cover-letter \
-	--pretty=mboxrd --topo-order \
-	$git_format_patch_opt \
-	"$revisions" ${restrict_revision+^$restrict_revision} \
-	>"$GIT_DIR/rebased-patches"
-ret=$?
-
-if test 0 != $ret
-then
-	rm -f "$GIT_DIR/rebased-patches"
-	case "$head_name" in
-	refs/heads/*)
-		git checkout -q "$head_name"
-		;;
-	*)
-		git checkout -q "$orig_head"
-		;;
-	esac
-
-	cat >&2 <<-EOF
-
-	git encountered an error while preparing the patches to replay
-	these revisions:
-
-	    $revisions
-
-	As a result, git cannot rebase them.
-	EOF
-	return $ret
-fi
-
-git am $git_am_opt --rebasing --resolvemsg="$resolvemsg" \
-	--patch-format=mboxrd \
-	$allow_rerere_autoupdate \
-	${gpg_sign_opt:+"$gpg_sign_opt"} <"$GIT_DIR/rebased-patches"
-ret=$?
-
-rm -f "$GIT_DIR/rebased-patches"
-
-if test 0 != $ret
-then
-	test -d "$state_dir" && write_basic_state
-	return $ret
-fi
-
-move_to_original_branch
-
-}