preserve the format of parameters with no value when calling maven-build and maven-chain

-Dfoo and -Dfoo= mean different things to the JVM, so make sure the format of the parameter on the command-line is carried through to the mvn invocation.

builder/kojid

@@ -579,7 +579,7 @@ class BuildRoot(object):
             cmd.append('-P%s' % ','.join(profiles))
         if props:
             for name, value in props.items():
-                if value:
+                if value is not None:
                     cmd.append('-D%s=%s' % (name, value))
                 else:
                     cmd.append('-D%s' % name)

cli/koji

@@ -1114,7 +1114,7 @@ def handle_maven_build(options, session, args):
     for prop in build_opts.properties:
         fields = prop.split('=', 1)
         if len(fields) != 2:
-            fields.append('')
+            fields.append(None)
         props[fields[0]] = fields[1]
     if props:
         opts['properties'] = props
@@ -1199,7 +1199,7 @@ def _maven_params(parser, opts, items):
             for prop in value.splitlines():
                 fields = prop.split('=', 1)
                 if len(fields) != 2:
-                    fields.append('')
+                    fields.append(None)
                 props[fields[0]] = fields[1]
             value = props
         elif name == 'envs':

www/kojiweb/taskinfo.chtml

@@ -15,9 +15,15 @@ $value
   #end if
 #end def
 
+#def printProperties($props)
+  #echo ', '.join([$v is not None and '%s=%s' % ($n, $v) or $str($n) for $n, $v in $props.items()])
+#end def
+
 #def printMap($vals, $prefix='')
   #for $key, $value in $vals.items()
-  #if $key != '__starstar'
+  #if $key == 'properties'
+  ${prefix}properties = $printProperties($value)
+  #elif $key != '__starstar'
   $prefix$key&nbsp;=&nbsp;$printValue($key, $value)<br/>
   #end if
   #end for