From afee8943fd120d9f99b3a5890cf2625e12815f5d Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 9 Oct 2016 19:50:16 +0100
Subject: dgit: Better error message if non-split-brain patch stack no longer
 applies

(due to new upstream version, or user messing with it). Closes:#833025.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 debian/changelog |  3 +++
 dgit             | 13 +++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/debian/changelog b/debian/changelog
index 8c3311a..f836390 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -44,6 +44,9 @@ dgit (1.5~~) unstable; urgency=medium
   * New tag format (for dgit view) archive/debian/VERSION.
   * Before committing to push, check that .dsc and .changes correspond.
     Closes:#800060.
+  * Better error message if non-split-brain patch stack no longer
+    applies (due to new upstream version, or user messing with it).
+    Closes:#833025.
 
   Infrastructure:
   * Better error handling in dgit-repos-policy-debian.
diff --git a/dgit b/dgit
index fa926dd..c1b1c25 100755
--- a/dgit
+++ b/dgit
@@ -4456,8 +4456,17 @@ sub quilt_fixup_multipatch ($$$) {
 
     ensuredir '.pc';
 
-    runcmd qw(sh -ec),
-        'exec dpkg-source --before-build . >/dev/null';
+    my @bbcmd = (qw(sh -ec), 'exec dpkg-source --before-build . >/dev/null');
+    $!=0; $?=-1;
+    if (system @bbcmd) {
+	failedcmd @bbcmd if $? < 0;
+	fail <<END;
+failed to apply your git tree's patch stack (from debian/patches/) to
+ the corresponding upstream tarball(s).  Your source tree and .orig
+ are probably too inconsistent.  dgit can only fix up certain kinds of
+ anomaly (depending on the quilt mode).  See --quilt= in dgit(1).
+END
+    }
 
     changedir '..';
 
-- 
cgit v1.2.3