tests: Add a test case for epoch 0 in rpmdb pkglist

Basically we're choosing the libdnf behavior of omitting `Epoch: 0` which IMO is
the sane thing to do even though in *theory* they're different RPMs but
who would ever ship both without incrementing release/etc?

More information in: https://github.com/projectatomic/rpm-ostree/pull/187

Closes: #1198
Approved by: cgwalters

tests/common/libtest.sh

@@ -385,6 +385,8 @@ get_obj_path() {
 # $2+ - optional, treated as directive/value pairs
 build_rpm() {
     local name=$1; shift
+    # Unset, not zero https://github.com/projectatomic/rpm-ostree/issues/349
+    local epoch=""
     local version=1.0
     local release=1
     local arch=x86_64
@@ -415,7 +417,7 @@ EOF
             echo "Conflicts: $arg" >> $spec;;
         post_args)
             post_args="$arg";;
-        version|release|arch|build|install|files|pretrans|pre|post|posttrans)
+        version|release|epoch|arch|build|install|files|pretrans|pre|post|posttrans)
             declare $section="$arg";;
         transfiletriggerin)
             transfiletriggerin_patterns="$arg";
@@ -434,6 +436,7 @@ EOF
     cat >> $spec << EOF
 Version: $version
 Release: $release
+${epoch:+Epoch: $epoch}
 BuildArch: $arch
 
 %description

tests/vmcheck/test-layering-basic.sh

@@ -59,7 +59,9 @@ assert_file_has_content err.txt "See https://github.com/projectatomic/rpm-ostree
 
 echo "ok failed to install in /opt and /usr/local"
 
-vm_build_rpm foo
+# Explicit epoch of 0 as it's a corner case:
+# https://github.com/projectatomic/rpm-ostree/issues/349
+vm_build_rpm foo epoch 0
 vm_rpmostree pkg-add foo-1.0
 vm_cmd ostree refs |grep /foo/> refs.txt
 pkgref=$(head -1 refs.txt)
@@ -71,6 +73,10 @@ rm -f refs.txt refdata.txt
 # This will cover things like us failing to break hardlinks for the rpmdb,
 # as well as rofiles-fuse
 vm_cmd ostree fsck
+vm_cmd ostree show --print-metadata-key rpmostree.rpmdb.pkglist \
+       $(vm_get_deployment_info 0 checksum) > variant-pkglist.txt
+# No 0: in EVR
+assert_file_has_content_literal 'variant-pkglist.txt' "('foo', '1.0-1', 'x86_64')"
 echo "ok pkg-add foo"
 
 vm_reboot