Bug 414831 - Preserve line delimiters when writing xml

Change-Id: Ib6c023fb73193f3b15450f52cefcc67068d1398d
Also-by: Andrew Gvozdev <angvoz.dev@gmail.com>
Signed-off-by: Andrew Gvozdev <angvoz.dev@gmail.com>
Signed-off-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/17187

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/language/settings/providers/LanguageSettingsProvidersSerializer.java

@@ -36,6 +36,7 @@ import org.eclipse.cdt.core.settings.model.ICLanguageSettingEntry;
 import org.eclipse.cdt.core.settings.model.ICProjectDescription;
 import org.eclipse.cdt.core.settings.model.ICSettingEntry;
 import org.eclipse.cdt.internal.core.XmlUtil;
+import org.eclipse.cdt.internal.core.model.Util;
 import org.eclipse.cdt.internal.core.settings.model.CConfigurationSpecSettings;
 import org.eclipse.cdt.internal.core.settings.model.IInternalCCfgInfo;
 import org.eclipse.cdt.internal.core.settings.model.SettingsModelMessages;
@@ -557,7 +558,11 @@ public class LanguageSettingsProvidersSerializer {
 
 				try {
 					serializingLockWsp.acquire();
-					XmlUtil.serializeXml(doc, uriStoreWsp);
+					String eol = Util.getLineSeparator(uriStoreWsp);
+					if (eol == null) {
+						eol = Util.getDefaultLineSeparator();
+					}
+					XmlUtil.serializeXml(doc, uriStoreWsp, eol);
 					// manufacture events while inside the lock
 					events = createLanguageSettingsChangeEvents(broadcastingWorkspaceProviders);
 				} finally {
@@ -881,7 +886,11 @@ public class LanguageSettingsProvidersSerializer {
 				if (isWorkspaceStoreEmpty) {
 					new java.io.File(uriStoreWsp).delete();
 				} else {
-					XmlUtil.serializeXml(docStoreWsp, uriStoreWsp);
+					String eol = Util.getLineSeparator(uriStoreWsp);
+					if (eol == null) {
+						eol =  Util.getDefaultLineSeparator(project);
+					}
+					XmlUtil.serializeXml(docStoreWsp, uriStoreWsp, eol);
 				}
 
 				// manufacture the event only if serialization was successful

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/Util.java

@@ -16,6 +16,7 @@
 package org.eclipse.cdt.internal.core.model;
 
 import java.io.BufferedInputStream;
+import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -30,6 +31,7 @@ import org.eclipse.core.filesystem.EFS;
 import org.eclipse.core.filesystem.IFileInfo;
 import org.eclipse.core.filesystem.URIUtil;
 import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.ProjectScope;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
@@ -413,6 +415,9 @@ public class Util implements ICLogConstants {
 		return null;
 	}
 
+	/**
+	 * Returns value of line separator preference from the given preference node.
+	 */
 	private static String getLineSeparatorFromPreferences(Preferences node) {
 		try {
 			// be careful looking up for our node so not to create any nodes as side effect
@@ -425,38 +430,21 @@ public class Util implements ICLogConstants {
 	}
 
 	/**
-	 * Returns line separator appropriate for the given file. The returned value
+	 * Returns the first line separator found in the given file.
-	 * will be the first available value from the list below:
-	 * <ol>
-	 *   <li> Line separator currently used in that file.
-	 *   <li> Line separator defined in project preferences.
-	 *   <li> Line separator defined in instance preferences.
-	 *   <li> Line separator defined in default preferences.
-	 *   <li> Operating system default line separator.
-	 * </ol>
-	 * @param file the file for which line separator should be returned
-	 * @return line separator for the given file
 	 * 
-	 * Note: This was copied from org.eclipse.core.internal.utils.FileUtil
+	 * @param fileUri - URI if the file on the local file-system.
+	 * @return the first line separator in the given file or {@code null} if none was read.
 	 */
-	public static String getLineSeparator(IFile file) {
+	public static String getLineSeparator(URI fileUri) {
-		if (file.exists()) {
+		String value = null;
 		InputStream input = null;
 		try {
-				input = file.getContents();
+			java.io.File file = new java.io.File(fileUri);
-				int c = input.read();
+			if (file.exists()) {
-				while (c != -1 && c != '\r' && c != '\n')
+				input = new FileInputStream(file);
-					c = input.read();
+				value = getLineSeparator(input);
-				if (c == '\n')
-					return "\n"; //$NON-NLS-1$
-				if (c == '\r') {
-					if (input.read() == '\n')
-						return "\r\n"; //$NON-NLS-1$
-					return "\r"; //$NON-NLS-1$
 			}
-			} catch (CoreException e) {
+		} catch (Exception e) {
-				// ignore
-			} catch (IOException e) {
 			// ignore
 		} finally {
 			try {
@@ -466,13 +454,79 @@ public class Util implements ICLogConstants {
 				//ignore
 			}
 		}
+		return value;
 	}
-		Preferences rootNode = Platform.getPreferencesService().getRootNode();
+
+	/**
+	 * Returns the line separator for the given file. If line separator is not found in the file
+	 * default value for the project or workspace is returned.
+	 * 
+	 * @param file - the file to look for a line separator.
+	 * @return the line separator for the given file. The method does not return {@code null}.
+	 */
+	public static String getLineSeparator(IFile file) {
 		String value = null;
+		InputStream input = null;
+		try {
+			input = file.getContents();
+			value = getLineSeparator(input);
+		} catch (CoreException e) {
+			// ignore
+		} finally {
+			try {
+				if (input != null)
+					input.close();
+			} catch (IOException e) {
+				//ignore
+			}
+		}
+
+		if (value == null)
+			value = getDefaultLineSeparator(file.getProject());
+
+		return value;
+	}
+
+	/**
+	 * Returns default line separator for the given project. The returned value
+	 * will be the first available value from the list below:
+	 * <ol>
+	 *   <li> Line separator defined in project preferences.
+	 *   <li> Line separator defined in instance preferences.
+	 *   <li> Line separator defined in default preferences.
+	 *   <li> Operating system default line separator.
+	 * </ol>
+	 * 
+	 * @param project - the project. If {@code null} no project preferences are inquired.
+	 * @return line separator for the given project. The method does not return {@code null}.
+	 */
+	public static String getDefaultLineSeparator(IProject project) {
+		String value = null;
+		Preferences rootNode = Platform.getPreferencesService().getRootNode();
 		// if the file does not exist or has no content yet, try with project preferences
-		value = getLineSeparatorFromPreferences(rootNode.node(ProjectScope.SCOPE).node(file.getProject().getName()));
+		if (project != null) {
+			value = getLineSeparatorFromPreferences(rootNode.node(ProjectScope.SCOPE).node(project.getName()));
 			if (value != null)
 				return value;
+		}
+		value = getDefaultLineSeparator();
+		return value;
+	}
+
+	/**
+	 * Returns default line separator for the workspace. The returned value
+	 * will be the first available value from the list below:
+	 * <ol>
+	 *   <li> Line separator defined in instance preferences.
+	 *   <li> Line separator defined in default preferences.
+	 *   <li> Operating system default line separator.
+	 * </ol>
+	 * @return line separator for the workspace. The method does not return {@code null}.
+	 */
+	public static String getDefaultLineSeparator() {
+		Preferences rootNode = Platform.getPreferencesService().getRootNode();
+		String value = null;
+
 		// try with instance preferences
 		value = getLineSeparatorFromPreferences(rootNode.node(InstanceScope.SCOPE));
 		if (value != null)
@@ -485,6 +539,31 @@ public class Util implements ICLogConstants {
 		return LINE_SEPARATOR;
 	}
 
+	/**
+	 * Returns the first line separator used by the input stream.
+	 * 
+	 * @param input - input stream to inspect.
+	 * @return line separator for the given input stream or {@code null} if no line separator was read.
+	 */
+	private static String getLineSeparator(InputStream input) {
+		try {
+			int c = input.read();
+			while (c != -1 && c != '\r' && c != '\n')
+				c = input.read();
+			if (c == '\n')
+				return "\n"; //$NON-NLS-1$
+			if (c == '\r') {
+				int c2 = input.read();
+				if (c2 == '\n')
+					return "\r\n"; //$NON-NLS-1$
+				return "\r"; //$NON-NLS-1$
+			}
+		} catch (IOException e) {
+			// ignore
+		}
+		return null;
+	}
+
 	/**
 	 * Return true if the file is not a directory and has length > 0
 	 */

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/xml/XmlProjectDescriptionStorage.java

@@ -121,7 +121,6 @@ public class XmlProjectDescriptionStorage extends AbstractCProjectDescriptionSto
 	static final String CONFIGURATION = "cconfiguration"; //$NON-NLS-1$
 
 	private static final QualifiedName LOAD_FLAG = new QualifiedName(CCorePlugin.PLUGIN_ID, "descriptionLoadded"); //$NON-NLS-1$
-	private static final String LINE_SEPARATOR = "line.separator"; //$NON-NLS-1$
 
 	public XmlProjectDescriptionStorage(CProjectDescriptionStorageTypeProxy type, IProject project, Version version) {
 		super(type, project, version);
@@ -573,12 +572,8 @@ public class XmlProjectDescriptionStorage extends AbstractCProjectDescriptionSto
 				// Get the ProjectDescription as a utf-8 string
 				stream = write(element);
 				utfString = stream.toString("UTF-8"); //$NON-NLS-1$
-
+				String eol = Util.getLineSeparator(projectFile);
-				// Make sure we keep the same line separator if the file exists
+				utfString = XmlUtil.replaceLineSeparatorInternal(utfString, eol);
-				// or use the preferences if it's a new file
-				String fileLineSeparator = Util.getLineSeparator(projectFile);
-				String sysLineSeparator = System.getProperty(LINE_SEPARATOR);
-				utfString = utfString.replace(sysLineSeparator, fileLineSeparator);
 			} finally {
 				if (stream != null)
 					stream.close(); // Cleanup the stream

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/errorparsers/ErrorParserExtensionManager.java

@@ -35,6 +35,7 @@ import org.eclipse.cdt.core.errorparsers.ErrorParserNamedWrapper;
 import org.eclipse.cdt.core.errorparsers.RegexErrorParser;
 import org.eclipse.cdt.core.errorparsers.RegexErrorPattern;
 import org.eclipse.cdt.internal.core.XmlUtil;
+import org.eclipse.cdt.internal.core.model.Util;
 import org.eclipse.core.filesystem.URIUtil;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
@@ -314,7 +315,11 @@ public class ErrorParserExtensionManager {
 				}
 			}
 
-			XmlUtil.serializeXml(doc, getStoreURI(STORAGE_ERRORPARSER_EXTENSIONS));
+			URI uri = getStoreURI(STORAGE_ERRORPARSER_EXTENSIONS);
+			String eol = Util.getLineSeparator(uri);
+			if (eol == null)
+				eol =  Util.getDefaultLineSeparator();
+			XmlUtil.serializeXml(doc, uri, eol);
 
 		} catch (Exception e) {
 			throw new CoreException(CCorePlugin.createStatus("Failed serializing to file " + STORAGE_ERRORPARSER_EXTENSIONS, e)); //$NON-NLS-1$

core/org.eclipse.cdt.core/utils/org/eclipse/cdt/internal/core/XmlUtil.java

@@ -17,6 +17,7 @@ import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
 import java.net.URI;
 
 import javax.xml.parsers.DocumentBuilder;
@@ -31,6 +32,7 @@ import javax.xml.transform.stream.StreamResult;
 
 import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.resources.ResourcesUtil;
+import org.eclipse.cdt.internal.core.model.Util;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;
@@ -45,8 +47,10 @@ import org.w3c.dom.NodeList;
  *
  */
 public class XmlUtil {
+	private static final String ENCODING_UTF_8 = "UTF-8"; //$NON-NLS-1$
 	private static final String EOL_XML = "\n"; //$NON-NLS-1$
 	private static final String DEFAULT_IDENT = "\t"; //$NON-NLS-1$
+	private static String LINE_SEPARATOR = System.getProperty("line.separator"); //$NON-NLS-1$
 
 	/**
 	 * Convenience method to create new XML DOM Document.
@@ -267,28 +271,26 @@ public class XmlUtil {
 	 *
 	 * @param doc - DOM Document to serialize.
 	 * @param uriLocation - URI of the file.
+	 * @param lineSeparator - line separator.
+	 * 
 	 * @throws IOException in case of problems with file I/O
 	 * @throws TransformerException in case of problems with XML output
 	 */
-	public static void serializeXml(Document doc, URI uriLocation) throws IOException, TransformerException {
+	public static void serializeXml(Document doc, URI uriLocation, String lineSeparator) throws IOException, TransformerException, CoreException {
 		XmlUtil.prettyFormat(doc);
 
 		java.io.File storeFile = new java.io.File(uriLocation);
 		if (!storeFile.exists()) {
 			storeFile.createNewFile();
 		}
-		TransformerFactory transformerFactory = TransformerFactory.newInstance();
-		Transformer transformer = transformerFactory.newTransformer();
-		transformer.setOutputProperty(OutputKeys.METHOD, "xml");	//$NON-NLS-1$
-		transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); //$NON-NLS-1$
-		transformer.setOutputProperty(OutputKeys.INDENT, "yes");	//$NON-NLS-1$
 
-		XmlUtil.prettyFormat(doc);
+		String utfString = new String(toByteArray(doc), ENCODING_UTF_8);
-		DOMSource source = new DOMSource(doc);
+		utfString = XmlUtil.replaceLineSeparatorInternal(utfString, lineSeparator);
-		StreamResult result = new StreamResult(getFileOutputStreamWorkaround(storeFile));
-		transformer.transform(source, result);
 
-		result.getOutputStream().close();
+		FileOutputStream output = getFileOutputStreamWorkaround(storeFile);
+		output.write(utfString.getBytes(ENCODING_UTF_8));
+
+		output.close();
 		ResourcesUtil.refreshWorkspaceFiles(uriLocation);
 	}
 
@@ -338,7 +340,7 @@ public class XmlUtil {
 			ByteArrayOutputStream stream = new ByteArrayOutputStream();
 			Transformer transformer = TransformerFactory.newInstance().newTransformer();
 			transformer.setOutputProperty(OutputKeys.METHOD, "xml"); //$NON-NLS-1$
-			transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); //$NON-NLS-1$
+			transformer.setOutputProperty(OutputKeys.ENCODING, ENCODING_UTF_8);
 			transformer.setOutputProperty(OutputKeys.INDENT, "yes"); //$NON-NLS-1$
 			DOMSource source = new DOMSource(doc);
 			StreamResult result = new StreamResult(stream);
@@ -350,6 +352,23 @@ public class XmlUtil {
 		}
 	}
 
+	/**
+	 * <b>Do not use outside of CDT.</b> This method is a workaround for {@link javax.xml.transform.Transformer}
+	 * not being able to specify the line separator. This method replaces a string generated by
+	 * {@link javax.xml.transform.Transformer} which contains the system line.separator with the line separators
+	 * from an existing file or the preferences if it's a new file.
+	 *
+	 * @param string - the string to be replaced
+	 * @param lineSeparator - line separator to be used in the string
+	 * 
+	 * @noreference This method is not intended to be referenced by clients.
+	 *    This is an internal method which ideally should be made private.
+	 */
+	public static String replaceLineSeparatorInternal(String string, String lineSeparator) {
+		string = string.replace(LINE_SEPARATOR, lineSeparator);
+		return string;
+	}
+
 	/**
 	 * Serialize XML Document into a workspace file.<br/>
 	 * Note: clients should synchronize access to this method.
@@ -361,12 +380,19 @@ public class XmlUtil {
 	public static void serializeXml(Document doc, IFile file) throws CoreException {
 		XmlUtil.prettyFormat(doc);
 
-		InputStream input = new ByteArrayInputStream(toByteArray(doc));
+		try {
+			String utfString = new String(toByteArray(doc), ENCODING_UTF_8);
+			String lineSeparator = Util.getLineSeparator(file);
+			utfString = XmlUtil.replaceLineSeparatorInternal(utfString, lineSeparator);
+			InputStream input = new ByteArrayInputStream(utfString.getBytes(ENCODING_UTF_8));
+
 			if (file.exists()) {
 				file.setContents(input, IResource.FORCE, null);
 			} else {
 				file.create(input, IResource.FORCE, null);
 			}
+		} catch (UnsupportedEncodingException e) {
+		}
 	}
 
 	/**