Bug 552102: [R-Help] Add support to exclude packages from indexing by a
Java property

Change-Id: I26dbc3e20096a2732594e9270915dc9b45a89b87
diff --git a/rhelp/org.eclipse.statet.rhelp.core/src/org/eclipse/statet/internal/rhelp/core/index/REnvIndexWriter.java b/rhelp/org.eclipse.statet.rhelp.core/src/org/eclipse/statet/internal/rhelp/core/index/REnvIndexWriter.java
index 48dedf4..ffb8d17 100644
--- a/rhelp/org.eclipse.statet.rhelp.core/src/org/eclipse/statet/internal/rhelp/core/index/REnvIndexWriter.java
+++ b/rhelp/org.eclipse.statet.rhelp.core/src/org/eclipse/statet/internal/rhelp/core/index/REnvIndexWriter.java
@@ -172,6 +172,15 @@
 	static {
 		IGNORE_PKG_NAMES= new ArrayList<>();
 		IGNORE_PKG_NAMES.add("translations"); //$NON-NLS-1$
+		
+		String s= System.getProperty("org.eclipse.statet.r.rhelp.PkgsToExclude.names"); //$NON-NLS-1$
+		if (s != null && !(s= s.trim()).isEmpty()) {
+			for (final String name : s.split(",")) { //$NON-NLS-1$
+				if (!name.isEmpty() && !IGNORE_PKG_NAMES.contains(name)) {
+					IGNORE_PKG_NAMES.add(name);
+				}
+			}
+		}
 	}