gather: Support dotarch in DNF backend

The documentation claims that dotarch syntax is supported for additional
packages. For yum backend this seems to be handled automatically, but
the dnf backend could not interpret this.

This patch checks if a package is specified in the syntax and contains a
valid architecture. If so, the query will honor the arch.

JIRA: RHELCMP-11728
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

pungi/gather_dnf.py

@@ -26,6 +26,7 @@ import pungi.common
 import pungi.dnf_wrapper
 import pungi.multilib_dnf
 import pungi.util
+from pungi import arch_utils
 from pungi.linker import Linker
 from pungi.profiler import Profiler
 from pungi.util import DEBUG_PATTERNS
@@ -500,9 +501,16 @@ class Gather(GatherBase):
                                 name__glob=pattern[:-2]
                             ).apply()
                         else:
-                            pkgs = self.q_binary_packages.filter(
-                                name__glob=pattern
-                            ).apply()
+                            kwargs = {"name__glob": pattern}
+                            if "." in pattern:
+                                # The pattern could be name.arch. Check if the
+                                # arch is valid, and if yes, make a more
+                                # specific query.
+                                name, arch = pattern.split(".", 1)
+                                if arch in arch_utils.arches:
+                                    kwargs["name__glob"] = name
+                                    kwargs["arch__eq"] = arch
+                            pkgs = self.q_binary_packages.filter(**kwargs).apply()
 
                 if not pkgs:
                     self.logger.error("No package matches pattern %s" % pattern)