Add tests for IMA signature deletion too

Normally IMA signatures should only be deleted with an explicit
rpmsign --delfilesign, but in case the are misplaced outside the
immutable region they get thrown out by rpmsign. This is expected
and desired behavior, it's simply the wrong place to place to put
them and not something we want to encourage in any way.

tests/rpmsigdig.at

@@ -1842,6 +1842,28 @@ rpm -qp --qf "[%{filenames}:%{filesignatures}\n]" /data/RPMS/imatest-1.0-1.fc34.
 /usr/share/example2:030204a598255400473045022100c10943795bff5d9c0db53dd4f8e4b845615fd08a2be295c30a80f5bdb4e6a41302203038840cc6abaab92acb56cb3e3ce520b17f22ff7444a8d5d0f703a44d5307a3
 ],
 [ignore])
+
+RPMTEST_CHECK([[
+cp /data/RPMS/imatest-1.0-1.fc34.noarch.rpm .
+rpmsign --delsign imatest-1.0-1.fc34.noarch.rpm
+rpm -qp --qf "[%{filenames}:%{filesignatures}\n]" imatest-1.0-1.fc34.noarch.rpm
+]],
+[0],
+[/usr/share/example1:030204a598255400483046022100e5117bdafa73baaeb1f1dc46ecaa46981a62d417745a33532572b63dc6d95d16022100c789107ac5b91e2d915e1df3c7b78414f6b3f50899d44c1de381d0e938dfc82b
+/usr/share/example2:030204a598255400473045022100c10943795bff5d9c0db53dd4f8e4b845615fd08a2be295c30a80f5bdb4e6a41302203038840cc6abaab92acb56cb3e3ce520b17f22ff7444a8d5d0f703a44d5307a3
+],
+[])
+
+RPMTEST_CHECK([[
+cp /data/RPMS/imatest-1.0-1.fc34.noarch.rpm .
+rpmsign --delfilesign imatest-1.0-1.fc34.noarch.rpm
+rpm -qp --qf "[%{filenames}:%{filesignatures}\n]" imatest-1.0-1.fc34.noarch.rpm
+]],
+[0],
+[/usr/share/example1:(none)
+/usr/share/example2:(none)
+],
+[])
 RPMTEST_CLEANUP
 
 
@@ -1862,4 +1884,18 @@ rpm -qp hello-2.0-1.x86_64-badima.rpm
 [hello-2.0-1.x86_64
 ],
 [])
+
+# NORMALLY --delsign shouldn't delete file signatures, but when they are
+# misplaced outside the immutable region, this is EXPECTED behavior.
+RPMTEST_CHECK([[
+rpm -qp --qf "[%{filenames}:%{filesignatures}\n]" hello-2.0-1.x86_64-badima.rpm
+]],
+[0],
+[/usr/bin/hello:(none)
+/usr/share/doc/hello-2.0:(none)
+/usr/share/doc/hello-2.0/COPYING:(none)
+/usr/share/doc/hello-2.0/FAQ:(none)
+/usr/share/doc/hello-2.0/README:(none)
+],
+[])
 RPMTEST_CLEANUP