libstfinv [TASK]: add assertion for taper

src/libs/libstfinv/stfinvfourier.cc

@@ -244,6 +244,8 @@ namespace stfinv {
       is >> Mtt1 >> Mtt2 >> Mtt3 >> Mtt4;
     }
     Mapplystftaper=this->parameterisset("irtap");
+    STFINV_assert((Mtt1<=Mtt2) && (Mtt2<=Mtt3) && (Mtt3<=Mtt4),
+                  "ERROR: taper definition times not in increasing order");
 
     STFINV_debug(Mdebug&1, "STFFourierDomainEngine::initialize()",
                  "this->nsamples()=" << this->nsamples() << " " <<