python: Split "semanage import" into two transactions

First transaction applies all deletion operations, so that there are no
collisions when applying the rest of the changes.

Fixes:
  # semanage port -a -t http_cache_port_t -r s0 -p tcp 3024
  # semanage export | semanage import
  ValueError: Port tcp/3024 already defined

Signed-off-by: Vit Mojzis <vmojzis@redhat.com>

python/semanage/semanage

@@ -852,10 +852,29 @@ def handleImport(args):
     trans = seobject.semanageRecords(args)
     trans.start()
 
+    deleteCommands = []
+    commands = []
+    # separate commands for deletion from the rest so they can be
+    # applied in a separate transaction
     for l in sys.stdin.readlines():
         if len(l.strip()) == 0:
             continue
+        if "-d" in l or "-D" in l:
+            deleteCommands.append(l)
+        else:
+            commands.append(l)
 
+    if deleteCommands:
+        importHelper(deleteCommands)
+        trans.finish()
+        trans.start()
+
+    importHelper(commands)
+    trans.finish()
+
+
+def importHelper(commands):
+    for l in commands:
         try:
             commandParser = createCommandParser()
             args = commandParser.parse_args(mkargv(l))
@@ -869,8 +888,6 @@ def handleImport(args):
         except KeyboardInterrupt:
             sys.exit(0)
 
-    trans.finish()
-
 
 def setupImportParser(subparsers):
     importParser = subparsers.add_parser('import', help=_('Import local customizations'))