Resolve the local repository path relative to the multi module directory

If a user specify a relative path in the settings.xml this currently
leads a bit to unspecified behavior. Java would then resolve it to the
current working directory what might give desired results on the
commandline (but sometimes also unexpected ones) but in the IDE it is
not really controllable.

This now resolves the local repository path against the multi module
directory what is the only user controllable constant directory we can
offer here at the moment.

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/embedder/MavenExecutionContext.java

@@ -165,20 +165,21 @@ protected MavenExecutionRequest newExecutionRequest() throws CoreException {
           .orElseGet(workspaceConfiguration::getSettingsLocations);
       if(request == null) {
         //create a fresh one ....
-        request = createExecutionRequest(workspaceConfiguration, containerLookup, mavenSettingsLocations);
+        request = createExecutionRequest(workspaceConfiguration, containerLookup, mavenSettingsLocations,
+            multiModuleProjectDirectory);
         request.setBaseDirectory(basedir);
       } else {
         //update existing configuration, we might have copied from an outer context here, but if the multi-module directory is different, we need to update some things...
         Settings settings = MavenPlugin.getMaven().getSettings(mavenSettingsLocations);
         File requestLocalRepositoryPath = request.getLocalRepositoryPath();
-        File settingsLocalRepositoryPath = getLocalRepositoryPath(settings);
+        File settingsLocalRepositoryPath = getLocalRepositoryPath(settings, multiModuleProjectDirectory);
         if(!pathEquals(requestLocalRepositoryPath, settingsLocalRepositoryPath)) {
           updateLocalRepository(request, settingsLocalRepositoryPath, containerLookup);
         }
         //TODO maybe also need to update user properties?!?
         updateSettingsFiles(request, mavenSettingsLocations);
+        request.setMultiModuleProjectDirectory(multiModuleProjectDirectory);
       }
-      request.setMultiModuleProjectDirectory(multiModuleProjectDirectory);
     }
     return request;
   }
@@ -198,16 +199,14 @@ private boolean pathEquals(File file1, File file2) {
   }
 
   static MavenExecutionRequest createExecutionRequest(IMavenConfiguration mavenConfiguration, IComponentLookup lookup,
-      MavenSettingsLocations settingsLocations) throws CoreException {
+      MavenSettingsLocations settingsLocations, File multiModuleProjectDirectory) throws CoreException {
     MavenExecutionRequest request = new DefaultMavenExecutionRequest();
     // this causes problems with unexpected "stale project configuration" error markers
     // need to think how to manage ${maven.build.timestamp} properly inside workspace
     //request.setStartTime( new Date() );
     Settings settings = MavenPlugin.getMaven().getSettings(settingsLocations);
     updateSettingsFiles(request, settingsLocations);
-
     //and settings are actually derived from IMavenConfiguration
-
     File userToolchainsFile = MavenCli.DEFAULT_USER_TOOLCHAINS_FILE;
     if(mavenConfiguration.getUserToolchainsFile() != null) {
       userToolchainsFile = new File(mavenConfiguration.getUserToolchainsFile());
@@ -219,7 +218,7 @@ static MavenExecutionRequest createExecutionRequest(IMavenConfiguration mavenCon
       throw new CoreException(Status.error(Messages.MavenImpl_error_no_exec_req, ex));
     }
 
-    updateLocalRepository(request, getLocalRepositoryPath(settings), lookup);
+    updateLocalRepository(request, getLocalRepositoryPath(settings, multiModuleProjectDirectory), lookup);
     request.setOffline(mavenConfiguration.isOffline());
 
     request.getUserProperties().put("m2e.version", MavenPluginActivator.getVersion()); //$NON-NLS-1$
@@ -231,6 +230,7 @@ static MavenExecutionRequest createExecutionRequest(IMavenConfiguration mavenCon
     request.setCacheTransferError(true);
 
     request.setGlobalChecksumPolicy(mavenConfiguration.getGlobalChecksumPolicy());
+    request.setMultiModuleProjectDirectory(multiModuleProjectDirectory);
     return request;
   }
 
@@ -259,12 +259,14 @@ private static void updateLocalRepository(MavenExecutionRequest request, File lo
     request.setLocalRepositoryPath(localRepository.getBasedir());
   }
 
-  private static File getLocalRepositoryPath(Settings settings) {
+  private static File getLocalRepositoryPath(Settings settings, File multiModuleProjectDirectory) {
     String localRepositoryPath = settings.getLocalRepository();
     if(localRepositoryPath == null) {
       return RepositorySystem.defaultUserLocalRepository;
     }
-    return new File(localRepositoryPath);
+      //Actually maven would resolve these against the current working directory, 
+      //as we have no such thing available the best we can use here is the root folder of the multimodule directory
+      return new File(multiModuleProjectDirectory, localRepositoryPath).getAbsoluteFile();
   }
 
   @Override

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/embedder/PlexusContainerManager.java

@@ -346,7 +346,8 @@ protected void configure() {
       IMavenConfiguration workspaceConfiguration = IMavenConfiguration.getWorkspaceConfiguration();
       MavenExecutionRequest request = MavenExecutionContext.createExecutionRequest(mavenConfiguration,
           wrap(container), mavenProperties.map(mavenCfg -> mavenCfg.getSettingsLocations(workspaceConfiguration))
-              .orElseGet(workspaceConfiguration::getSettingsLocations));
+              .orElseGet(workspaceConfiguration::getSettingsLocations),
+          multiModuleProjectDirectory);
       container.lookup(MavenExecutionRequestPopulator.class).populateDefaults(request);
       request.setBaseDirectory(multiModuleProjectDirectory);
       request.setMultiModuleProjectDirectory(multiModuleProjectDirectory);