From 6b3cdcf0d595efd96bc8c4220df87f7fd5aaef76 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 23 Apr 2018 00:32:43 +0100
Subject: [PATCH] git-debrebase: Implement make-patches

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 git-debrebase               | 38 +++++++++++++++++++++++++++++++++++++
 git-debrebase.1.pod         | 21 ++++++++++++++++++++
 git-debrebase.5.pod         |  1 +
 tests/tests/gdr-subcommands |  7 ++++---
 4 files changed, 64 insertions(+), 3 deletions(-)

diff --git a/git-debrebase b/git-debrebase
index 7d5d5bdd..7c8d54db 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -1362,6 +1362,44 @@ sub make_patches_staged ($) {
     };
 }
 
+sub make_patches ($) {
+    my ($head) = @_;
+    keycommits $head, 0, \&snag;
+    make_patches_staged $head;
+    my $out;
+    in_workarea sub {
+	my $ptree = cmdoutput @git, qw(write-tree --prefix=debian/patches/);
+	runcmd @git, qw(read-tree), $head;
+	read_tree_subdir 'debian/patches', $ptree;
+	$out = make_commit [$head], [
+            'Commit patch queue (exported by git-debrebase)',
+            '[git-debrebase: export and commit patches]',
+        ];
+    };
+    my $d = get_differs $head, $out;
+    if ($d == 0) {
+	return undef; # nothing to do
+    } elsif ($d == D_PAT_ADD) {
+	return $out; # OK
+    } else {
+	fail "Patch export produced patch amendments".
+	    " (abandoned output commit $out).".
+	    "  Try laundering first.";
+    }
+}
+
+sub cmd_make_patches () {
+    badusage "no arguments allowed" if @ARGV;
+    my $old_head = get_head();
+    my $new = make_patches $old_head;
+    snags_maybe_bail();
+    if (!$new) {
+	fail "No (more) patches to export." unless $opt_noop_ok;
+	return;
+    }
+    update_head_checkout $old_head, $new, 'make-patches';
+}
+
 sub cmd_convert_from_gbp () {
     badusage "needs 1 optional argument, the upstream git rev"
 	unless @ARGV<=1;
diff --git a/git-debrebase.1.pod b/git-debrebase.1.pod
index 9f82a7c3..5da53202 100644
--- a/git-debrebase.1.pod
+++ b/git-debrebase.1.pod
@@ -188,6 +188,27 @@ that its command line syntax is optimal.
 We may want to introduce an incompatible replacement syntax
 under the name C<new-upstream>.
 
+=item git-debrebase make-patches
+
+Generate patches in debian/patches/
+representing the changes made to upstream files.
+
+It is not normally necessary to run this command explicitly.
+When uploading to Debian,
+dgit and git-debrebase
+will cooperate to regenerate patches as necessary.
+When working with pure git remotes,
+the patches are not needed.
+
+Normally git-debrebase make-patches will
+require a laundered branch.
+(A laundered branch does not contain any patches.)
+But if there are already some patches made by
+git-debrebase make-patches,
+and all that has happened is that more
+changes to upstream files have been committed,
+running it again can add the missing patches.
+
 =item git-debrebase convert-from-gbp [<upstream-commit-ish>]
 
 Cnnverts a gbp patches-unapplied branch
diff --git a/git-debrebase.5.pod b/git-debrebase.5.pod
index 6ae094f0..5cfa3761 100644
--- a/git-debrebase.5.pod
+++ b/git-debrebase.5.pod
@@ -501,6 +501,7 @@ The full set of annotations is:
   [git-debrebase upstream-combine . PIECE[ PIECE...]: new upstream]
   [git-debrebase anchor: new upstream NEW-UPSTREAM-VERSION, merge]
   [git-debrebase: new upstream NEW-UPSTREAM-VERSION, changelog]
+  [git-debrebase: export and commit patches]
 
   [git-debrebase convert-from-gbp: drop patches]
   [git-debrebase anchor: declare upstream]
diff --git a/tests/tests/gdr-subcommands b/tests/tests/gdr-subcommands
index 2a90cdc0..9d50b6c0 100755
--- a/tests/tests/gdr-subcommands
+++ b/tests/tests/gdr-subcommands
@@ -138,7 +138,7 @@ make_check () {
 		git reset --hard HEAD^1
 		;;
 	P*)
-		t-dgit -wgf --quilt=check quilt-fixup
+		t-dgit -wgf --quilt=nofix quilt-fixup
 		git diff HEAD~ debian/patches | egrep .
 		git diff --quiet HEAD~ -- ':.' ':!debian/patches'
 		git reset --hard HEAD~
@@ -160,6 +160,7 @@ make_check () {
 }
 
 Ec="F:No ongoing git-debrebase session"
+Ep="F:Patch export produced patch amendments"
 
 # input state:
 #  stitched?		st'd	st'd	unst'd	unst'd
@@ -174,8 +175,8 @@ subcmd	stitch		Ns	Nu	Sltf	Stf
 subcmd	prepush		Ns	Nu	Sltf	Stf
 subcmd	quick		ns	Sl	Sltf	Sl
 subcmd	conclude	"$Ec"	"$Ec"	Sltf	Sl
-#subcmd	make-patches	sPft	sPft	uPft	uPft
-#subcmd	dgit-upload-hook Psft	Psft	SPft	SPft
+subcmd	make-patches	sPft	"$Ep"	uPft	"$Ep"
+#subcmd	dgit-upload-hook Psft	"$Ep"	SPft	"$Ep"
 #
 # result codes, each one is a check:
 #   E:$pat	} this is an error (must come first)
-- 
2.30.2