use UTF-8 as default encoding in the Terminal (#1020)

the rest of Eclipse now uses UTF-8 as default encoding.

The tm.terminal code reverts to null when the encoding
begins with "Default" and this leads to UTF-8 being
selected from Charset.defaultEncoding instead of ISO-8859
when the displayed default value is selected.

Co-authored-by: Philipp SALZGEBER <philipp.salzgeber@bachmann.info>

NewAndNoteworthy/CDT-12.0.md

@@ -52,6 +52,15 @@ The View Performance preference page, which is CDT specific, has been relocated
 This only affects where in the Preferences tree the page is located, the preferences and key names have not changed.
 In addition, this page is always visible.
 
+# Terminal
+
+## Default encoding for terminal is now UTF-8
+
+For a [while](https://eclipse.dev/eclipse/news/4.24/platform.html#explicit-encoding-workspaces), the default encoding in Eclipse has been UTF-8.
+Starting in CDT 12, the Terminal will now default to UTF-8.
+
+<p align="center"><img src="images/CDT-12.0-default-terminal-encoding.png"></p>
+
 # API Changes, current and planned
 
 ## Breaking API changes

terminal/plugins/org.eclipse.tm.terminal.connector.ssh/src/org/eclipse/tm/terminal/connector/ssh/controls/SshWizardConfigurationPanel.java

@@ -232,7 +232,7 @@ public class SshWizardConfigurationPanel extends AbstractExtendedConfigurationPa
 				if (encoding == null || "null".equals(encoding)) { //$NON-NLS-1$
 					String defaultEncoding = getSelectionEncoding();
 					encoding = defaultEncoding != null && !"".equals(defaultEncoding.trim()) ? defaultEncoding.trim() //$NON-NLS-1$
-							: "ISO-8859-1"; //$NON-NLS-1$
+							: "UTF-8"; //$NON-NLS-1$
 				}
 				setEncoding(encoding);
 			} else {

terminal/plugins/org.eclipse.tm.terminal.control/about.properties

@@ -1,5 +1,5 @@
 ###############################################################################
-# Copyright (c) 2018, 2024 Contributors to the Eclipse Foundation
+# Copyright (c) 2018, 2025 Contributors to the Eclipse Foundation
 #
 # See the NOTICE file(s) distributed with this work for additional
 # information regarding copyright ownership.
@@ -24,7 +24,7 @@ blurb=TM Terminal Control\n\
 Version: {featureVersion}\n\
 Build id: {0}\n\
 \n\
-Copyright (c) 2018, 2024 Contributors to the Eclipse Foundation
+Copyright (c) 2018, 2025 Contributors to the Eclipse Foundation
 \n\
 See the NOTICE file(s) distributed with this work for additional\n\
 information regarding copyright ownership.\n\

terminal/plugins/org.eclipse.tm.terminal.control/src/org/eclipse/tm/internal/terminal/emulator/VT100Emulator.java

@@ -1210,7 +1210,7 @@ public class VT100Emulator implements ControlListener {
 		}
 
 		try {
-			terminal.getOutputStream().write(reply.getBytes("ISO-8859-1")); //$NON-NLS-1$
+			terminal.getOutputStream().write(reply.getBytes("UTF-8")); //$NON-NLS-1$
 			terminal.getOutputStream().flush();
 		} catch (IOException ex) {
 			Logger.log("Caught IOException!"); //$NON-NLS-1$

terminal/plugins/org.eclipse.tm.terminal.test/src/org/eclipse/tm/internal/terminal/connector/TerminalConnectorFactoryTest.java

@@ -61,7 +61,7 @@ public class TerminalConnectorFactoryTest extends TestCase {
 
 		@Override
 		public String getEncoding() {
-			return "ISO-8859-1"; //$NON-NLS-1$
+			return "UTF-8"; //$NON-NLS-1$
 		}
 
 		@Override

terminal/plugins/org.eclipse.tm.terminal.test/src/org/eclipse/tm/internal/terminal/connector/TerminalConnectorTest.java

@@ -61,7 +61,7 @@ public class TerminalConnectorTest extends TestCase {
 
 		@Override
 		public String getEncoding() {
-			return "ISO-8859-1"; //$NON-NLS-1$
+			return "UTF-8"; //$NON-NLS-1$
 		}
 
 		@Override

terminal/plugins/org.eclipse.tm.terminal.view.ui/src/org/eclipse/tm/terminal/view/ui/panels/AbstractExtendedConfigurationPanel.java

@@ -537,7 +537,7 @@ public abstract class AbstractExtendedConfigurationPanel extends AbstractConfigu
 			List<String> encodings = new ArrayList<>();
 
 			// Default encoding
-			encodings.add("Default (ISO-8859-1)"); //$NON-NLS-1$
+			encodings.add("Default (UTF-8)"); //$NON-NLS-1$
 
 			// The currently selected IDE encoding from the preferences
 			String ideEncoding = getResourceEncoding();
@@ -612,7 +612,7 @@ public abstract class AbstractExtendedConfigurationPanel extends AbstractConfigu
 		Assert.isNotNull(encoding);
 
 		if (encodingCombo != null && !encodingCombo.isDisposed()) {
-			int index = encodingCombo.indexOf("ISO-8859-1".equals(encoding) ? "Default (ISO-8859-1)" : encoding); //$NON-NLS-1$ //$NON-NLS-2$
+			int index = encodingCombo.indexOf("UTF-8".equals(encoding) ? "Default (UTF-8)" : encoding); //$NON-NLS-1$ //$NON-NLS-2$
 			if (index != -1)
 				encodingCombo.select(index);
 			else {
@@ -642,7 +642,7 @@ public abstract class AbstractExtendedConfigurationPanel extends AbstractConfigu
 	protected boolean isEncodingValid() {
 		try {
 			String encoding = getEncoding();
-			return Charset.isSupported(encoding != null ? encoding : "ISO-8859-1"); //$NON-NLS-1$
+			return Charset.isSupported(encoding != null ? encoding : "UTF-8"); //$NON-NLS-1$
 		} catch (IllegalCharsetNameException e) {
 			return false;
 		}

terminal/plugins/org.eclipse.tm.terminal.view.ui/src/org/eclipse/tm/terminal/view/ui/tabs/TabFolderManager.java

@@ -833,8 +833,8 @@ public class TabFolderManager extends PlatformObject implements ISelectionProvid
 				buffer.append(" - "); //$NON-NLS-1$
 
 				String encoding = terminal.getEncoding();
-				if (encoding == null || "ISO-8859-1".equals(encoding)) { //$NON-NLS-1$
-					encoding = "Default (ISO-8859-1)"; //$NON-NLS-1$
+				if (encoding == null || "UTF-8".equals(encoding)) { //$NON-NLS-1$
+					encoding = "Default (UTF-8)"; //$NON-NLS-1$
 				}
 				buffer.append(NLS.bind(Messages.TabFolderManager_encoding, encoding));