[backend] Fix empty packages.gz testsubmit/trunk/20190927.012743submit/devel/20190730.075427release-20190125

in case no packages are produced, dpkg-scanpackages outputs nothing,
causing and empty Packages.new. test against non-zero filesize, and
remove Packages.new if it exists.

Change-Id: I97061e4c8a5bf12c708dae56efba77ad1940aae0

1 files changed, 2 insertions, 1 deletions

diff --git a/src/backend/bs_publish b/src/backend/bs_publish
index f784273..3a0413f 100755
--- a/src/backend/bs_publish
+++ b/src/backend/bs_publish
@@ -620,7 +620,7 @@ sub deleterepo_susetags {
 
 sub compress_and_rename {
   my($file) =@_;
-  if (-f "$file.new") {
+  if (-s "$file.new") {
     unlink("$file");
     link("$file.new", "$file");
     qsystem('gzip', '-9', '-n', '-f', "$file.new") && print "    gzip $file.new failed: $?\n";
@@ -628,6 +628,7 @@ sub compress_and_rename {
     unlink("$file.gz");
     rename("$file.new.gz", "$file.gz");
   } else {
+    unlink("$file.new");
     unlink("$file");
     unlink("$file.gz");
   }