How to create apply a patch that contains changes in multiple projects?

Eclipse has a nice feature to apply patches (context menu of a project: Team->Apply Patch....). If you have multiple projects under CVS control, then you can create a patch that contains changes from multiple projects. The patch looks slightly odd, because id adds some additional lines that tell eclipse which projects a file belongs to. This has is new in eclipse 3.2 (bug 110481).

However if you have a patch created with diff outside eclipse that contains files from multiple projects, eclipse cannot apply the patch.

To apply my multi project patches I wrote a small Eclipse Monkey script that converts a patch on the clipboard to a Eclipse Workspace Patch 1.0, by adding some additional lines.

To install and run the script:

• Install Eclipse Monkey (if you have not already installed it)
  
• Copy the script below (including the odd lines at the beginning and the end) to the clipboard
  
• In the Monkey menu do Paste New Script
  
• Now you can convert patches to Eclipse Workspace Patch 1.0, by copying that patch to the clipboard and running Monkey->Tools->Convert patch in clipboard to workspace patch

--- Came wiffling through the eclipsey wood ---
/*
 * Menu: Tools > Convert patch in clipboard to workspace patch
 * Kudos: Michael Scharf(eclipsemonkey @ scharf . gr)
 * License: EPL 1.0
 */

// pseudo imports
var ArrayList=Packages.java.util.ArrayList;
var Pattern=Packages.java.util.regex.Pattern;
var StringBuffer=Packages.java.lang.StringBuffer;
var BufferedReader=Packages.java.io.BufferedReader;
var StringReader=Packages.java.io.StringReader;
var ResourcesPlugin=Packages.org.eclipse.core.resources.ResourcesPlugin;
var MessageDialog=Packages.org.eclipse.jface.dialogs.MessageDialog;

var dnd=Packages.org.eclipse.swt.dnd;


function main() {
  var patch = getFromClipboard();
  if(patch == null) {
    showMessage("The clipboard does not contain a string!");
  } else {
    // is this already a workspace patch?
    // the (?m) makes sure that the ^ matches the beginning of a line
    // and not just the beginning of the string!
    var pattern=Pattern.compile("(?m)^### Eclipse Workspace Patch 1.0");
    if(pattern.matcher(patch).find()) {
      showMessage("This is already a Workspace Patch!\n" + 
                  "It contains a line beginning with:\n" + 
                  "\"### Eclipse Workspace Patch 1.0\"");
    } else {
      var messages =  new StringBuffer();
      patch = convertToWoskspacePatch(patch, messages);
      // has it been converted?
      if(patch == null) {
     showMessage("The clipboard does not contain a valid patch.");
      } else {
        // OK let's put it on the clipboard
        putOnClipboard(patch);
        showMessage("Patch converted to clipboard\n\n" + messages.toString());
      }
     }
  }
}

// show a simple message dialog
function showMessage(message) {
 MessageDialog.openInformation(
     window.getShell(), "Convert patch to workspace patch", message);

}
function convertToWoskspacePatch(patch, messages) {
  var reader =  new BufferedReader( new StringReader(patch));
  var patchBeginPattern = Pattern.compile("^(---|[+][+][+]|RCS file:)\\s+([^\t\n,]+)");
  var result =  new StringBuffer();
  result.append("### Eclipse Workspace Patch 1.0\n");
  var projects = ResourcesPlugin.getWorkspace().getRoot().getProjects();
  var guessedProjects =  new ArrayList();
  var patchFound = false;
  var line;
  var prevLine = null;
  var hunkFound = false;
  while((line = reader.readLine()) != null) {
    var m = patchBeginPattern.matcher(line);
    if(m.find()) {
      patchFound = true;
      var fileName = m.group(2).trim();
      var pathSegments = fileName.split("[/\\\\]");
      var segment = 0; // the segment in the path that is the project
      var projectName = null;
      for(var i = 0; i < pathSegments.length; i++) {
        var name = pathSegments[i];
        if(isProjectName(projects, name)) {
          projectName = name;
          segment = i;
          hunkFound=true;
          // report every guessed project only once
          if(!guessedProjects.contains(projectName)) {
            messages.append("Guessed Project: ");
            messages.append(projectName);
            messages.append("\n");
            guessedProjects.add(projectName);
          }
          break;
        }
      }
      if(projectName != null) {
        result.append("#P ");
        result.append(projectName);
        result.append("\n");
        result.append("Index: ");
        // concat the remaining path segments
        for(var j = segment + 1; j < pathSegments.length; j++) {
          if(j != segment + 1) result.append("/");
          result.append(pathSegments[j]);
        }
        result.append("\n");
        result.append("===================================================================\n");
      }
    }
    if(line.startsWith("+++")) {
      if(!hunkFound) {
        messages.append("No project found for: ");
        messages.append(fileName);
        messages.append("\n");
      }
      hunkFound = false;
    }
    if(prevLine != null) {
      result.append(prevLine);
      result.append("\n");
    }
    prevLine = line;
  }
  if(prevLine != null) {
    result.append(prevLine);
    result.append("\n");
  }
  reader.close();
  if(!patchFound) 
    return null;
  return result.toString();
}

function isProjectName(projects, name) {
  // is the name a name of a project? 
  for(var i = 0; i < projects.length; i++) {
    if(projects[i].getName().equals(name)) 
     return true;
  }
  // ok let's guess...
  if(name.startsWith("com.") || name.startsWith("org.")) {
    return true;
  }
  return false;
}
function putOnClipboard(str) {
  var clipboard =  new dnd.Clipboard(window.getShell().getDisplay());
  try {
    clipboard.setContents([str], [dnd.TextTransfer.getInstance()]);
  } finally {
    clipboard.dispose();
  }
}
function getFromClipboard() {
  var textTransfer = dnd.TextTransfer.getInstance();
  var clipboard =  new dnd.Clipboard(window.getShell().getDisplay());
  try {
    return clipboard.getContents(textTransfer);
  } finally {
    clipboard.dispose();
  }
}

--- And burbled as it ran! ---