diff -Nru samtools-1.13/debian/changelog samtools-1.13/debian/changelog
--- samtools-1.13/debian/changelog	2021-10-24 18:25:10.000000000 +0000
+++ samtools-1.13/debian/changelog	2021-10-25 18:53:03.000000000 +0000
@@ -1,3 +1,10 @@
+samtools (1.13-4) unstable; urgency=medium
+
+  * [650b7a7] d/rules: only disable executable bit if test package is built.
+    (Closes: #997834)
+
+ -- Étienne Mollier <emollier@debian.org>  Mon, 25 Oct 2021 20:53:03 +0200
+
 samtools (1.13-3) unstable; urgency=medium
 
   * [ee4c97e] d/rules: fix several issues in manual pages.
diff -Nru samtools-1.13/debian/rules samtools-1.13/debian/rules
--- samtools-1.13/debian/rules	2021-10-24 18:24:06.000000000 +0000
+++ samtools-1.13/debian/rules	2021-10-24 22:08:12.000000000 +0000
@@ -58,7 +58,9 @@
 	    sed -i '1s?#!/usr/bin/env \+perl?#!/usr/bin/perl?' $${pscript} ; \
 	done
 	# Disable the executable bit on a dataset.
-	chmod 0644 debian/samtools-test/usr/share/samtools/test/ampliconclip/ac_test.bed
+	if [ -d debian/samtools-test ] \
+	; then chmod 0644 debian/samtools-test/usr/share/samtools/test/ampliconclip/ac_test.bed \
+	; fi
 
 override_dh_installchangelogs:
 	dh_installchangelogs NEWS