Fixed bug in expanding expressions containing dummy indices. [V.Kisil]

[ginac.git] / ginac / ncmul.cpp

diff --git a/ginac/ncmul.cpp b/ginac/ncmul.cpp
index 4424253ce4369c9a1ebb5c271d12e500ca08638b..eeadf4e7feb4fa6acf7b48db84062b049e502526 100644 (file)
--- a/ginac/ncmul.cpp
+++ b/ginac/ncmul.cpp
@@ -30,6 +30,7 @@
 #include "mul.h"
 #include "matrix.h"
 #include "archive.h"
+#include "indexed.h"
 #include "utils.h"
 
 namespace GiNaC {
@@ -167,10 +168,25 @@ ex ncmul::expand(unsigned options) const
 
        intvector k(number_of_adds);
 
+       /* Rename indices in the static members of the product */
+       exvector expanded_seq_mod;
+       size_t j = 0;
+       size_t i;
+       for (i=0; i<expanded_seq.size(); i++) {
+               if (i == positions_of_adds[j]) {
+                       expanded_seq_mod.push_back(_ex1);
+                       j++;
+               } else {
+                       expanded_seq_mod.push_back(rename_dummy_indices_uniquely(ncmul(expanded_seq_mod), expanded_seq[i]));
+               }
+       }
+
        while (true) {
-               exvector term = expanded_seq;
-               for (size_t i=0; i<number_of_adds; i++)
-                       term[positions_of_adds[i]] = expanded_seq[positions_of_adds[i]].op(k[i]);
+               exvector term = expanded_seq_mod;
+               for (i=0; i<number_of_adds; i++) {
+                       term[positions_of_adds[i]] = rename_dummy_indices_uniquely(ncmul(term), expanded_seq[positions_of_adds[i]].op(k[i]));
+               }
+
                distrseq.push_back((new ncmul(term, true))->
                                    setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0)));