[JGIT PATCH 9/9] Add debug-show-commands to display the command table

@@ -10,3 +10,5 @@ org.spearce.jgit.pgm.Push
 org.spearce.jgit.pgm.RevList
 org.spearce.jgit.pgm.ShowRev
 org.spearce.jgit.pgm.Tag
+
+org.spearce.jgit.pgm.debug.ShowCommands

@@ -120,6 +120,13 @@ public class CommandRef {
 	}
 
 	/**
+	 * @return loader for {@link #getImplementationClassName()}.
+	 */
+	public ClassLoader getImplementationClassLoader() {
+		return impl.getClassLoader();
+	}
+
+	/**
 	 * @return a new instance of the command implementation.
 	 */
 	public TextBuiltin create() {

@@ -0,0 +1,78 @@
+package org.spearce.jgit.pgm.debug;
+
+import java.net.URL;
+
+import org.kohsuke.args4j.Option;
+import org.spearce.jgit.pgm.Command;
+import org.spearce.jgit.pgm.CommandCatalog;
+import org.spearce.jgit.pgm.CommandRef;
+import org.spearce.jgit.pgm.TextBuiltin;
+
+@Command(usage = "Display a list of all registered jgit commands")
+class ShowCommands extends TextBuiltin {
+	@Option(name = "--pretty", usage = "alter the detail shown")
+	private Format pretty = Format.USAGE;
+
+	@Override
+	protected void run() throws Exception {
+		final CommandRef[] list = CommandCatalog.all();
+
+		int width = 0;
+		for (final CommandRef c : list)
+			width = Math.max(width, c.getName().length());
+		width += 2;
+
+		for (final CommandRef c : list) {
+			System.err.print(c.isCommon() ? '*' : ' ');
+			System.err.print(' ');
+
+			System.err.print(c.getName());
+			for (int i = c.getName().length(); i < width; i++)
+				System.err.print(' ');
+
+			pretty.print(c);
+			System.err.println();
+		}
+		System.err.println();
+	}
+
+	static enum Format {
+		/** */
+		USAGE {
+			void print(final CommandRef c) {
+				System.err.print(c.getUsage());
+			}
+		},
+
+		/** */
+		CLASSES {
+			void print(final CommandRef c) {
+				System.err.print(c.getImplementationClassName());
+			}
+		},
+
+		/** */
+		URLS {
+			void print(final CommandRef c) {
+				final ClassLoader ldr = c.getImplementationClassLoader();
+
+				String cn = c.getImplementationClassName();
+				cn = cn.replace('.', '/') + ".class";
+
+				final URL url = ldr.getResource(cn);
+				if (url == null) {
+					System.err.print("!! NOT FOUND !!");
+					return;
+				}
+
+				String rn = url.toExternalForm();
+				if (rn.endsWith(cn))
+					rn = rn.substring(0, rn.length() - cn.length());
+
+				System.err.print(rn);
+			}
+		};
+
+		abstract void print(CommandRef c);
+	}
+}