Tests and fix added for #309 (inplace mpi doubling).
diff --git a/tests/suites/test_suite_mpi.data b/tests/suites/test_suite_mpi.data
index 56817cc..76c9e3e 100644
--- a/tests/suites/test_suite_mpi.data
+++ b/tests/suites/test_suite_mpi.data
@@ -295,6 +295,12 @@
 Test mpi_add_mpi #2
 mpi_add_mpi:10:"643808006803554439230129854961492699151386107534013432918073439524138264842370630061369715394739134090922937332590384720397133335969549256322620979036686633213903952966175107096769180017646161851573147596390153":10:"56125680981752282333498088313568935051383833838594899821664631784577337171193624243181360054669678410455329112434552942717084003541384594864129940145043086760031292483340068923506115878221189886491132772739661669044958531131327771":10:"56125680981752282334141896320372489490613963693556392520816017892111350604111697682705498319512049040516698827829292076808006940873974979584527073481012636016353913462376755556720019831187364993587901952757307830896531678727717924"
 
+Base test mpi_add_mpi inplace #1
+mpi_add_mpi_inplace:10:"12345678":10:"24691356"
+
+Test mpi_add_mpi inplace #2 
+mpi_add_mpi_inplace:10:"643808006803554439230129854961492699151386107534013432918073439524138264842370630061369715394739134090922937332590384720397133335969549256322620979036686633213903952966175107096769180017646161851573147596390153":10:"1287616013607108878460259709922985398302772215068026865836146879048276529684741260122739430789478268181845874665180769440794266671939098512645241958073373266427807905932350214193538360035292323703146295192780306"
+
 Test mpi_add_int #1
 mpi_add_int:10:"2039568783564019774057658669290345772801939933143482630947726464532830627227012776329":9871232:10:"2039568783564019774057658669290345772801939933143482630947726464532830627227022647561"