Validate filepath and filename to prevent path traversal (#1604)

Validate filepath and filename to prevent path traversal in modification
command and provide validations for editor plugin.

Co-authored-by: René Pfeuffer <rene.pfeuffer@cloudogu.com>

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/HgModifyCommand.java

@@ -93,6 +93,11 @@ public class HgModifyCommand extends AbstractWorkingCopyCommand implements Modif
               private void addFileToHg(File file) {
                 workingRepository.workingCopy().add(file.getAbsolutePath());
               }
+
+              @Override
+              public boolean isProtectedPath(Path path) {
+                return path.startsWith(workingRepository.getDirectory().toPath().normalize().resolve(".hg"));
+              }
             });
           } catch (IOException e) {
             throwInternalRepositoryException("could not execute command on repository", e);