Fix DiffConfig to understand "copy" resp. "copies" for diff.renames property.

Rename detection should be considered enabled if
diff.renames config property is set to "copy" or "copies", instead of
throwing IllegalArgumentException.

Change-Id: If55d955e37235d4d00f5b0febd6aa10c0e27814e

org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffConfig.java

@@ -43,8 +43,12 @@
 
 package org.eclipse.jgit.diff;
 
+import java.text.MessageFormat;
+
+import org.eclipse.jgit.JGitText;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Config.SectionParser;
+import org.eclipse.jgit.util.StringUtils;
 
 /** Keeps track of diff related configuration options. */
 public class DiffConfig {
@@ -55,15 +59,28 @@ public DiffConfig parse(final Config cfg) {
 		}
 	};
 
+	/** Permissible values for {@code diff.renames}. */
+	public static enum RenameDetectionType {
+		/** Rename detection is disabled. */
+		FALSE,
+
+		/** Rename detection is enabled. */
+		TRUE,
+
+		/** Copies should be detected too. */
+		COPY
+	}
+
 	private final boolean noPrefix;
 
-	private final boolean renames;
+	private final RenameDetectionType renameDetectionType;
 
 	private final int renameLimit;
 
 	private DiffConfig(final Config rc) {
 		noPrefix = rc.getBoolean("diff", "noprefix", false);
-		renames = rc.getBoolean("diff", "renames", false);
+		renameDetectionType = parseRenameDetectionType(rc.getString("diff",
+				null, "renames"));
 		renameLimit = rc.getInt("diff", "renamelimit", 200);
 	}
 
@@ -74,11 +91,37 @@ public boolean isNoPrefix() {
 
 	/** @return true if rename detection is enabled by default. */
 	public boolean isRenameDetectionEnabled() {
-		return renames;
+		return renameDetectionType != RenameDetectionType.FALSE;
+	}
+
+	/** @return type of rename detection to perform. */
+	public RenameDetectionType getRenameDetectionType() {
+		return renameDetectionType;
 	}
 
 	/** @return limit on number of paths to perform inexact rename detection. */
 	public int getRenameLimit() {
 		return renameLimit;
 	}
+
+	private static RenameDetectionType parseRenameDetectionType(
+			final String renameString) {
+		if (renameString == null)
+			return RenameDetectionType.FALSE;
+		else if (StringUtils.equalsIgnoreCase("copy", renameString)
+				|| StringUtils.equalsIgnoreCase("copies", renameString))
+			return RenameDetectionType.COPY;
+		else {
+			final Boolean renameBoolean = StringUtils
+					.toBooleanOrNull(renameString);
+			if (renameBoolean == null)
+				throw new IllegalArgumentException(MessageFormat.format(
+						JGitText.get().enumValueNotSupported2, "diff",
+						"renames", renameString));
+			else if (renameBoolean.booleanValue())
+				return RenameDetectionType.TRUE;
+			else
+				return RenameDetectionType.FALSE;
+		}
+	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/util/StringUtils.java

@@ -121,15 +121,8 @@ public static boolean equalsIgnoreCase(final String a, final String b) {
 	}
 
 	/**
-	 * Parse a string as a standard Git boolean value.
-	 * <p>
-	 * The terms {@code yes}, {@code true}, {@code 1}, {@code on} can all be
-	 * used to mean {@code true}.
-	 * <p>
-	 * The terms {@code no}, {@code false}, {@code 0}, {@code off} can all be
-	 * used to mean {@code false}.
-	 * <p>
-	 * Comparisons ignore case, via {@link #equalsIgnoreCase(String, String)}.
+	 * Parse a string as a standard Git boolean value. See
+	 * {@link #toBooleanOrNull(String)}.
 	 *
 	 * @param stringValue
 	 *            the string to parse.
@@ -142,21 +135,45 @@ public static boolean toBoolean(final String stringValue) {
 		if (stringValue == null)
 			throw new NullPointerException(JGitText.get().expectedBooleanStringValue);
 
+		final Boolean bool = toBooleanOrNull(stringValue);
+		if (bool == null)
+			throw new IllegalArgumentException(MessageFormat.format(JGitText.get().notABoolean, stringValue));
+
+		return bool.booleanValue();
+	}
+
+	/**
+	 * Parse a string as a standard Git boolean value.
+	 * <p>
+	 * The terms {@code yes}, {@code true}, {@code 1}, {@code on} can all be
+	 * used to mean {@code true}.
+	 * <p>
+	 * The terms {@code no}, {@code false}, {@code 0}, {@code off} can all be
+	 * used to mean {@code false}.
+	 * <p>
+	 * Comparisons ignore case, via {@link #equalsIgnoreCase(String, String)}.
+	 *
+	 * @param stringValue
+	 *            the string to parse.
+	 * @return the boolean interpretation of {@code value} or null in case the
+	 *         string does not represent a boolean value
+	 */
+	public static Boolean toBooleanOrNull(final String stringValue) {
+		if (stringValue == null)
+			return null;
+
 		if (equalsIgnoreCase("yes", stringValue)
 				|| equalsIgnoreCase("true", stringValue)
 				|| equalsIgnoreCase("1", stringValue)
-				|| equalsIgnoreCase("on", stringValue)) {
-			return true;
-
-		} else if (equalsIgnoreCase("no", stringValue)
+				|| equalsIgnoreCase("on", stringValue))
+			return Boolean.TRUE;
+		else if (equalsIgnoreCase("no", stringValue)
 				|| equalsIgnoreCase("false", stringValue)
 				|| equalsIgnoreCase("0", stringValue)
-				|| equalsIgnoreCase("off", stringValue)) {
-			return false;
-
-		} else {
-			throw new IllegalArgumentException(MessageFormat.format(JGitText.get().notABoolean, stringValue));
-		}
+				|| equalsIgnoreCase("off", stringValue))
+			return Boolean.FALSE;
+		else
+			return null;
 	}
 
 	/**