CheckPath: Better validation routine

common/CheckPath.h

@@ -8,7 +8,10 @@
 #include "JFJochException.h"
 
 inline void CheckPath(const std::string &s) {
-    if (!s.empty() && s.front() == '/')
+    // CheckPath looks validates that s can be a valid file name
+    // (in practice with an added suffix, .e.g. _master.h5 or .tiff)
+    // It avoids paths going outside of a given directory
+    if (!s.empty() && (s.front() == '/' || s.back() != '/'))
         throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                               "Path cannot start with slash");
     if (s.size() >= 3 && s.substr(0,3) == "../")