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-git-plugin/src/main/java/sonia/scm/repository/spi/GitModifyCommand.java

@@ -176,6 +176,11 @@ public class GitModifyCommand extends AbstractGitCommand implements ModifyComman
       }
     }
 
+    @Override
+    public boolean isProtectedPath(Path path) {
+      return path.startsWith(getClone().getRepository().getDirectory().toPath().normalize());
+    }
+
     @Override
     public File getWorkDir() {
       return workDir;