MergeFormatter{Pass}: Use Charset instead of String

Deprecate constructors and methods taking a character set name as
a String, in favor of new variants taking a Charset.

Change-Id: I616c601daf232fa17610dba1087fd902030d46ea
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/MergeAlgorithmTest.java

@@ -302,7 +302,7 @@ public class MergeAlgorithmTest {
 		MergeResult r = new MergeAlgorithm().merge(RawTextComparator.DEFAULT,
 				T(commonBase), T(ours), T(theirs));
 		ByteArrayOutputStream bo=new ByteArrayOutputStream(50);
-		fmt.formatMerge(bo, r, "B", "O", "T", Constants.CHARACTER_ENCODING);
+		fmt.formatMerge(bo, r, "B", "O", "T", UTF_8);
 		return new String(bo.toByteArray(), UTF_8);
 	}
 

org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/MergerTest.java

@@ -972,7 +972,7 @@ public class MergerTest extends RepositoryTestCase {
 			merger.getMergeResults().get("file");
 			try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
 				fmt.formatMerge(out, merger.getMergeResults().get("file"),
-						"BASE", "OURS", "THEIRS", UTF_8.name());
+						"BASE", "OURS", "THEIRS", UTF_8);
 				String expected = "<<<<<<< OURS\n"
 						+ "1master\n"
 						+ "=======\n"

org.eclipse.jgit/src/org/eclipse/jgit/merge/MergeFormatter.java

@@ -45,6 +45,7 @@ package org.eclipse.jgit.merge;
 
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -72,15 +73,46 @@ public class MergeFormatter {
 	 *            " or ">>>>>>> " conflict markers. The
 	 *            names for the sequences are given in this list
 	 * @param charsetName
-	 *            the name of the characterSet used when writing conflict
+	 *            the name of the character set used when writing conflict
 	 *            metadata
 	 * @throws java.io.IOException
+	 * @deprecated Use
+	 *             {@link #formatMerge(OutputStream, MergeResult, List, Charset)}
+	 *             instead.
 	 */
+	@Deprecated
 	public void formatMerge(OutputStream out, MergeResult<RawText> res,
 			List<String> seqName, String charsetName) throws IOException {
 		new MergeFormatterPass(out, res, seqName, charsetName).formatMerge();
 	}
 
+	/**
+	 * Formats the results of a merge of {@link org.eclipse.jgit.diff.RawText}
+	 * objects in a Git conformant way. This method also assumes that the
+	 * {@link org.eclipse.jgit.diff.RawText} objects being merged are line
+	 * oriented files which use LF as delimiter. This method will also use LF to
+	 * separate chunks and conflict metadata, therefore it fits only to texts
+	 * that are LF-separated lines.
+	 *
+	 * @param out
+	 *            the output stream where to write the textual presentation
+	 * @param res
+	 *            the merge result which should be presented
+	 * @param seqName
+	 *            When a conflict is reported each conflicting range will get a
+	 *            name. This name is following the "&lt;&lt;&lt;&lt;&lt;&lt;&lt;
+	 *            " or "&gt;&gt;&gt;&gt;&gt;&gt;&gt; " conflict markers. The
+	 *            names for the sequences are given in this list
+	 * @param charset
+	 *            the character set used when writing conflict metadata
+	 * @throws java.io.IOException
+	 * @since 5.2
+	 */
+	public void formatMerge(OutputStream out, MergeResult<RawText> res,
+			List<String> seqName, Charset charset) throws IOException {
+		new MergeFormatterPass(out, res, seqName, charset).formatMerge();
+	}
+
 	/**
 	 * Formats the results of a merge of exactly two
 	 * {@link org.eclipse.jgit.diff.RawText} objects in a Git conformant way.
@@ -100,17 +132,51 @@ public class MergeFormatter {
 	 * @param theirsName
 	 *            the name ranges from theirs should get
 	 * @param charsetName
-	 *            the name of the characterSet used when writing conflict
+	 *            the name of the character set used when writing conflict
 	 *            metadata
 	 * @throws java.io.IOException
+	 * @deprecated use
+	 *             {@link #formatMerge(OutputStream, MergeResult, String, String, String, Charset)}
+	 *             instead.
 	 */
-	@SuppressWarnings("unchecked")
+	@Deprecated
 	public void formatMerge(OutputStream out, MergeResult res, String baseName,
 			String oursName, String theirsName, String charsetName) throws IOException {
+		formatMerge(out, res, baseName, oursName, theirsName,
+				Charset.forName(charsetName));
+	}
+
+	/**
+	 * Formats the results of a merge of exactly two
+	 * {@link org.eclipse.jgit.diff.RawText} objects in a Git conformant way.
+	 * This convenience method accepts the names for the three sequences (base
+	 * and the two merged sequences) as explicit parameters and doesn't require
+	 * the caller to specify a List
+	 *
+	 * @param out
+	 *            the {@link java.io.OutputStream} where to write the textual
+	 *            presentation
+	 * @param res
+	 *            the merge result which should be presented
+	 * @param baseName
+	 *            the name ranges from the base should get
+	 * @param oursName
+	 *            the name ranges from ours should get
+	 * @param theirsName
+	 *            the name ranges from theirs should get
+	 * @param charset
+	 *            the character set used when writing conflict metadata
+	 * @throws java.io.IOException
+	 * @since 5.2
+	 */
+	@SuppressWarnings("unchecked")
+	public void formatMerge(OutputStream out, MergeResult res, String baseName,
+			String oursName, String theirsName, Charset charset)
+			throws IOException {
 		List<String> names = new ArrayList<>(3);
 		names.add(baseName);
 		names.add(oursName);
 		names.add(theirsName);
-		formatMerge(out, res, names, charsetName);
+		formatMerge(out, res, names, charset);
 	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/merge/MergeFormatterPass.java

@@ -46,6 +46,7 @@ package org.eclipse.jgit.merge;
 
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.charset.Charset;
 import java.util.List;
 
 import org.eclipse.jgit.diff.RawText;
@@ -59,19 +60,58 @@ class MergeFormatterPass {
 
 	private final List<String> seqName;
 
-	private final String charsetName;
+	private final Charset charset;
 
 	private final boolean threeWayMerge;
 
 	private String lastConflictingName; // is set to non-null whenever we are in
 										// a conflict
 
+	/**
+	 * @deprecated use
+	 *             {@link #MergeFormatterPass(OutputStream, MergeResult, List, Charset)}
+	 *             instead.
+	 * @param out
+	 *            the {@link java.io.OutputStream} where to write the textual
+	 *            presentation
+	 * @param res
+	 *            the merge result which should be presented
+	 * @param seqName
+	 *            When a conflict is reported each conflicting range will get a
+	 *            name. This name is following the "&lt;&lt;&lt;&lt;&lt;&lt;&lt;
+	 *            " or "&gt;&gt;&gt;&gt;&gt;&gt;&gt; " conflict markers. The
+	 *            names for the sequences are given in this list
+	 * @param charsetName
+	 *            the name of the character set used when writing conflict
+	 *            metadata
+	 */
+	@Deprecated
 	MergeFormatterPass(OutputStream out, MergeResult<RawText> res, List<String> seqName,
 			String charsetName) {
+		this(out, res, seqName, Charset.forName(charsetName));
+	}
+
+	/**
+	 *
+	 * @param out
+	 *            the {@link java.io.OutputStream} where to write the textual
+	 *            presentation
+	 * @param res
+	 *            the merge result which should be presented
+	 * @param seqName
+	 *            When a conflict is reported each conflicting range will get a
+	 *            name. This name is following the "&lt;&lt;&lt;&lt;&lt;&lt;&lt;
+	 *            " or "&gt;&gt;&gt;&gt;&gt;&gt;&gt; " conflict markers. The
+	 *            names for the sequences are given in this list
+	 * @param charset
+	 *            the character set used when writing conflict metadata
+	 */
+	MergeFormatterPass(OutputStream out, MergeResult<RawText> res,
+			List<String> seqName, Charset charset) {
 		this.out = new EolAwareOutputStream(out);
 		this.res = res;
 		this.seqName = seqName;
-		this.charsetName = charsetName;
+		this.charset = charset;
 		this.threeWayMerge = (res.getSequences().size() == 3);
 	}
 
@@ -133,7 +173,7 @@ class MergeFormatterPass {
 
 	private void writeln(String s) throws IOException {
 		out.beginln();
-		out.write((s + "\n").getBytes(charsetName)); //$NON-NLS-1$
+		out.write((s + "\n").getBytes(charset)); //$NON-NLS-1$
 	}
 
 	private void writeLine(RawText seq, int i) throws IOException {

org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java

@@ -46,10 +46,10 @@
  */
 package org.eclipse.jgit.merge;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.eclipse.jgit.diff.DiffAlgorithm.SupportedAlgorithm.HISTOGRAM;
 import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_DIFF_SECTION;
 import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_ALGORITHM;
-import static org.eclipse.jgit.lib.Constants.CHARACTER_ENCODING;
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
 
 import java.io.BufferedOutputStream;
@@ -1026,7 +1026,7 @@ public class ResolveMerger extends ThreeWayMerger {
 				db != null ? nonNullRepo().getDirectory() : null, inCoreLimit);
 		try {
 			new MergeFormatter().formatMerge(buf, result,
-					Arrays.asList(commitNames), CHARACTER_ENCODING);
+					Arrays.asList(commitNames), UTF_8);
 			buf.close();
 		} catch (IOException e) {
 			buf.destroy();