Implement git-quiltimport

Importing a quilt patch series into git is not very difficult
but parsing the patch descriptions and all of the other
minutia take a bit of effort to get right, so this automates it.

Since git and quilt complement each other it makes sense
to make it easy to go back and forth between the two.

If a patch is encountered that it cannot derive the author
from the user is asked.

Signed-off-by: Junio C Hamano <junkio@cox.net>

3 files changed, 162 insertions, 1 deletions

diff --git a/Documentation/git-quiltimport.txt b/Documentation/git-quiltimport.txt
new file mode 100644
index 0000000000..c66c82c61d
--- /dev/null
+++ b/Documentation/git-quiltimport.txt
@@ -0,0 +1,55 @@
+git-quiltimport(1)
+================
+
+NAME
+----
+git-quiltimport - Applies a quilt patchset onto the current branch
+
+
+SYNOPSIS
+--------
+[verse]
+'git-quiltimport' [--author <author>] [--patches <dir>]
+
+
+DESCRIPTION
+-----------
+Applies a quilt patchset onto the current git branch, preserving
+the patch boundaries, patch order, and patch descriptions present
+in the quilt patchset.
+
+For each patch the code attempts to extract the author from the
+patch description.  If that fails it falls back to the author
+specified with --author.  If the --author flag was not given
+the patch description is displayed and the user is asked to
+interactively enter the author of the patch.
+
+If a subject is not found in the patch description the patch name is
+preserved as the 1 line subject in the git description.
+
+OPTIONS
+-------
+--author Author Name <Author Email>::
+	The author name and email address to use when no author
+	information can be found in the patch description.
+
+--patches <dir>::
+	The directory to find the quilt patches and the
+	quilt series file.
+
+        The default for the patch directory is patches
+	or the value of the $QUILT_PATCHES environment
+	variable.
+
+Author
+------
+Written by Eric Biederman <ebiederm@lnxi.com>
+
+Documentation
+--------------
+Documentation by Eric Biederman <ebiederm@lnxi.com>
+
+GIT
+---
+Part of the gitlink:git[7] suite
+
diff --git a/Makefile b/Makefile
index 2149fb8cea..549f953b76 100644
--- a/Makefile
+++ b/Makefile
@@ -125,7 +125,7 @@ SCRIPT_SH = \
 	git-applymbox.sh git-applypatch.sh git-am.sh \
 	git-merge.sh git-merge-stupid.sh git-merge-octopus.sh \
 	git-merge-resolve.sh git-merge-ours.sh \
-	git-lost-found.sh
+	git-lost-found.sh git-quiltimport.sh
 
 SCRIPT_PERL = \
 	git-archimport.perl git-cvsimport.perl git-relink.perl \
diff --git a/git-quiltimport.sh b/git-quiltimport.sh
new file mode 100755
index 0000000000..dd4a198fb1
--- /dev/null
+++ b/git-quiltimport.sh
@@ -0,0 +1,106 @@
+#!/bin/sh
+USAGE='--author <author> --patches </path/to/quilt/patch/directory>'
+SUBDIRECTORY_ON=Yes
+. git-sh-setup
+
+quilt_author=""
+while case "$#" in 0) break;; esac
+do
+	case "$1" in
+	--au=*|--aut=*|--auth=*|--autho=*|--author=*)
+		quilt_author=$(expr "$1" : '-[^=]*\(.*\)')
+		shift
+		;;
+
+	--au|--aut|--auth|--autho|--author)
+		case "$#" in 1) usage ;; esac
+		shift
+		quilt_author="$1"
+		shift
+		;;
+
+	--pa=*|--pat=*|--patc=*|--patch=*|--patche=*|--patches=*)
+		QUILT_PATCHES=$(expr "$1" : '-[^=]*\(.*\)')
+		shift
+		;;
+
+	--pa|--pat|--patc|--patch|--patche|--patches)
+		case "$#" in 1) usage ;; esac
+		shift
+		QUILT_PATCHES="$1"
+		shift
+		;;
+
+	*)
+		break
+		;;
+	esac
+done
+
+# Quilt Author
+if [ -n "$quilt_author" ] ; then
+	quilt_author_name=$(expr "z$quilt_author" : 'z\(.*[^ ]\) *<.*') &&
+	quilt_author_email=$(expr "z$quilt_author" : '.*<\([^>]*\)') &&
+	test '' != "$quilt_author_name" &&
+	test '' != "$quilt_author_email" ||
+	die "malformatted --author parameter"
+fi
+
+# Quilt patch directory
+: ${QUILT_PATCHES:=patches}
+if ! [ -d "$QUILT_PATCHES" ] ; then
+	echo "The \"$QUILT_PATCHES\" directory does not exist."
+	exit 1
+fi
+
+# Temporay directories
+tmp_dir=.dotest
+tmp_msg="$tmp_dir/msg"
+tmp_patch="$tmp_dir/patch"
+tmp_info="$tmp_dir/info"
+
+
+# Find the intial commit
+commit=$(git-rev-parse HEAD)
+
+mkdir $tmp_dir || exit 2
+for patch_name in $(cat "$QUILT_PATCHES/series" | grep -v '^#'); do
+	echo $patch_name
+	(cat $QUILT_PATCHES/$patch_name | git-mailinfo "$tmp_msg" "$tmp_patch" > "$tmp_info") || exit 3
+
+	# Parse the author information
+	export GIT_AUTHOR_NAME=$(sed -ne 's/Author: //p' "$tmp_info")
+	export GIT_AUTHOR_EMAIL=$(sed -ne 's/Email: //p' "$tmp_info")
+	while test -z "$GIT_AUTHOR_EMAIL" && test -z "$GIT_AUTHOR_NAME" ; do
+		if [ -n "$quilt_author" ] ; then
+			GIT_AUTHOR_NAME="$quilt_author_name";
+			GIT_AUTHOR_EMAIL="$quilt_author_email";
+		else
+			echo "No author found in $patch_name";
+			echo "---"
+			cat $tmp_msg
+			echo -n "Author: ";
+			read patch_author
+
+			echo "$patch_author"
+
+			patch_author_name=$(expr "z$patch_author" : 'z\(.*[^ ]\) *<.*') &&
+			patch_author_email=$(expr "z$patch_author" : '.*<\([^>]*\)') &&
+			test '' != "$patch_author_name" &&
+			test '' != "$patch_author_email" &&
+			GIT_AUTHOR_NAME="$patch_author_name" &&
+			GIT_AUTHOR_EMAIL="$patch_author_email"
+		fi
+	done
+	export GIT_AUTHOR_DATE=$(sed -ne 's/Date: //p' "$tmp_info")
+	export SUBJECT=$(sed -ne 's/Subject: //p' "$tmp_info")
+	if [ -z "$SUBJECT" ] ; then
+		SUBJECT=$(echo $patch_name | sed -e 's/.patch$//')
+	fi
+
+	git-apply --index -C1 "$tmp_patch" &&
+	tree=$(git-write-tree) &&
+	commit=$((echo "$SUBJECT"; echo; cat "$tmp_msg") | git-commit-tree $tree -p $commit) &&
+	git-update-ref HEAD $commit || exit 4
+done
+rm -rf $tmp_dir || exit 5