[bugfix] util:system-property should be deterministic within the execution scope

Author: adamretter

exist-core/src/main/java/org/exist/xquery/XQueryContext.java

@@ -376,6 +376,9 @@ public class XQueryContext implements BinaryValueManager, Context {
     //For holding the environment variables
     private IMap<String, String> envs;
 
+    //For holding the Java System Properties
+    private IMap<String, String> props;
+
     private ContextUpdateListener updateListener = null;
 
     private boolean enableOptimizer = true;
@@ -2742,6 +2745,26 @@ public io.lacuna.bifurcan.IMap<String, String> getEnvironmentVariables() {
         return envs;
     }
 
+    /**
+     * Get Java System properties. The properties shall not change
+     * during execution of query.
+     *
+     * @return Map of Java System Properties
+     */
+    public io.lacuna.bifurcan.IMap<String, String> getJavaSystemProperties() {
+        if (props == null) {
+            final IMap<String, String> strProps = new LinearMap<>();
+            for (final Map.Entry<Object, Object> prop : System.getProperties().entrySet()) {
+                final Object value = prop.getValue();
+                if (value instanceof String) {
+                    strProps.put(prop.getKey().toString(), (String) value);
+                }
+            }
+            props = strProps.forked();
+        }
+        return props;
+    }
+
     /**
      * Gets the Effective user
      * i.e. the user that the query is executing as

exist-core/src/main/java/org/exist/xquery/functions/util/SystemProperty.java

@@ -60,7 +60,7 @@ public Sequence eval(final Sequence[] args, final Sequence contextSequence) thro
         final String key = args[0].getStringValue();
         String value = ExistSystemProperties.getInstance().getExistSystemProperty(key, null);
         if (value == null) {
-            value = System.getProperty(key);
+            value = context.getJavaSystemProperties().get(key, null);
         }
         return value == null ? Sequence.EMPTY_SEQUENCE : new StringValue(value);
     }