Avoid yielding blank lines with APT::Cmd::use-format=true

apt-private/private-list.cc

@@ -93,6 +93,7 @@ static void ListAllVersions(pkgCacheFile &CacheFile, pkgRecords &records,/*{{{*/
         Ver.end() == false; ++Ver)
    {
       ListSingleVersion(CacheFile, records, Ver, outs, include_summary);
+      outs << "\n";
    }
 }
 									/*}}}*/
@@ -148,7 +149,7 @@ bool DoList(CommandLine &Cmd)
    // FIXME: SORT! and make sorting flexible (alphabetic, by pkg status)
    // output the sorted map
    for (K = output_map.begin(); K != output_map.end(); ++K)
-      std::cout << (*K).second;
+      std::cout << (*K).second << std::endl;
 
 
    // be nice and tell the user if there is more to see

apt-private/private-output.cc

@@ -220,7 +220,7 @@ void ListSingleVersion(pkgCacheFile &CacheFile, pkgRecords &records,	/*{{{*/
       output = SubstVar(output, "${Version}", GetVersion(CacheFile, V));
       output = SubstVar(output, "${Description}", GetShortDescription(CacheFile, records, P));
       output = SubstVar(output, "${Origin}", GetArchiveSuite(CacheFile, V));
-      out << output << std::endl;
+      out << output;
    } else {
       // raring/linux-kernel version [upradable: new-version]
       //    description

test/integration/test-apt-cli-list

@@ -68,4 +68,7 @@ testequal "Listing...
 baz/unstable 2.0 all [upgradable from: 0.1]
 N: There are 2 additional versions. Please use the '-a' switch to see them." apt list baz -o quiet=0
 
-
+# test format strings for machine parseable output
+apt list -qq bar baz  -o APT::Cmd::use-format=true  -o APT::Cmd::format="\${Package} - \${installed:Version} - \${candidate:Version}" > output.txt
+testequal "bar - 1.0 - 1.0
+baz - 0.1 - 2.0" cat output.txt