From 7a9b155347c117dceb866095ce87f7c7b54d053f Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 16 Jul 2016 11:54:45 +0100
Subject: [PATCH] Split brain: With patches-unapplied trees, apply before
 running rules

Everywhere we invoke dpkg-buildpackage, check if we need to apply the
patches.  And at the end of every command that might have done this,
check if we did, and unapply them if so.

We don't try to unapply patches in case of error.  That seems likely
to be quite fragile.

Print a warning when we apply patches, suggesting ways to avoid the
need.
---
 dgit | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/dgit b/dgit
index fe1bff5f..7708fb54 100755
--- a/dgit
+++ b/dgit
@@ -64,6 +64,7 @@ our $quilt_mode;
 our $quilt_modes_re = 'linear|smash|auto|nofix|nocheck|gbp|unapplied';
 our $we_are_responder;
 our $initiator_tempdir;
+our $patches_applied_dirtily = 00;
 
 our %format_ok = map { $_=>1 } ("1.0","3.0 (native)","3.0 (quilt)");
 
@@ -3236,6 +3237,29 @@ sub quilt_fixup_editor () {
     exit 0;
 }
 
+sub maybe_apply_patches_dirtily () {
+    return unless $quilt_mode =~ m/gbp|unapplied/;
+    print STDERR <<END or die $!;
+
+dgit: Building, or cleaning with rules target, in patches-unapplied tree.
+dgit: Have to apply the patches - making the tree dirty.
+dgit: (Consider specifying --clean=git and (or) using dgit sbuild.)
+
+END
+    $patches_applied_dirtily = 01;
+    $patches_applied_dirtily |= 02 unless stat_exists '.pc';
+    runcmd qw(dpkg-source --before-build .);
+}
+
+sub maybe_unapply_patches_again () {
+    progress "dgit: Unapplying patches again to tidy up the tree."
+	if $patches_applied_dirtily;
+    runcmd qw(dpkg-source --after-build .)
+	if $patches_applied_dirtily & 01;
+    rmtree '.pc'
+	if $patches_applied_dirtily & 02;
+}
+
 #----- other building -----
 
 our $clean_using_builder;
@@ -3247,8 +3271,10 @@ our $clean_using_builder;
 sub clean_tree () {
     return if $clean_using_builder;
     if ($cleanmode eq 'dpkg-source') {
+	maybe_apply_patches_dirtily();
 	runcmd_ordryrun_local @dpkgbuildpackage, qw(-T clean);
     } elsif ($cleanmode eq 'dpkg-source-d') {
+	maybe_apply_patches_dirtily();
 	runcmd_ordryrun_local @dpkgbuildpackage, qw(-d -T clean);
     } elsif ($cleanmode eq 'git') {
 	runcmd_ordryrun_local @git, qw(clean -xdf);
@@ -3270,6 +3296,7 @@ sub cmd_clean () {
     badusage "clean takes no additional arguments" if @ARGV;
     notpushing();
     clean_tree();
+    maybe_unapply_patches_again();
 }
 
 sub build_prep () {
@@ -3391,8 +3418,10 @@ sub cmd_build {
     }
     if ($wantsrc < 2) {
 	push @dbp, changesopts_version();
+	maybe_apply_patches_dirtily();
 	runcmd_ordryrun_local @dbp;
     }
+    maybe_unapply_patches_again();
     printdone "build successful\n";
 }
 
@@ -3423,8 +3452,10 @@ sub cmd_gbp_build {
 	    push @cmd, "--git-debian-branch=".lbranch();
 	}
 	push @cmd, changesopts();
+	maybe_apply_patches_dirtily();
 	runcmd_ordryrun_local @cmd, @ARGV;
     }
+    maybe_unapply_patches_again();
     printdone "build successful\n";
 }
 sub cmd_git_build { cmd_gbp_build(); } # compatibility with <= 1.0
@@ -3451,9 +3482,11 @@ sub build_source {
     }
     $dscfn = dscfn($version);
     if ($our_cleanmode eq 'dpkg-source') {
+	maybe_apply_patches_dirtily();
 	runcmd_ordryrun_local @dpkgbuildpackage, qw(-us -uc -S),
 	    changesopts();
     } elsif ($our_cleanmode eq 'dpkg-source-d') {
+	maybe_apply_patches_dirtily();
 	runcmd_ordryrun_local @dpkgbuildpackage, qw(-us -uc -S -d),
 	    changesopts();
     } else {
@@ -3490,6 +3523,7 @@ sub build_source {
 sub cmd_build_source {
     badusage "build-source takes no additional arguments" if @ARGV;
     build_source();
+    maybe_unapply_patches_again();
     printdone "source built, results in $dscfn and $sourcechanges";
 }
 
@@ -3532,6 +3566,7 @@ sub cmd_sbuild {
 	    rename "$cf", "$cf.inmulti" or fail "$cf\{,.inmulti}: $!";
 	}
     }
+    maybe_unapply_patches_again();
     printdone "build successful, results in $multichanges\n" or die $!;
 }    
 
-- 
2.30.2