Smarter computation of the required space for the struct.

This commit was SVN r1090.

src/datatype/dt_create_struct.c

@@ -12,10 +12,19 @@ int lam_ddt_create_struct( int count, int* pBlockLength, long* pDisp,
     /* if we compute the total number of elements before we can
      * avoid increasing the size of the desc array often.
      */
-   for( disp = 0, i = 0; i < count; i++ ) {
-      disp += pTypes[i]->desc.used;
-      if( pBlockLength[i] != 1 ) disp += 2;
+    for( lastType = pTypes[0], lastBlock = 0, disp = 0, i = 0; i < count; i++ ) {
+        if( lastType == pTypes[i] ) {
+            lastBlock += pBlockLength[i];
+        } else {
+            disp += lastType->desc.used;
+            if( lastBlock != 1 ) disp += 2;
+            lastType = pTypes[i];
+            lastBlock = pBlockLength[i];
         }
+    }
+    disp += lastType->desc.used;
+    if( lastBlock != 1 ) disp += 2;
+
     lastType = pTypes[0];
     lastBlock = pBlockLength[0];
     lastExtent = lastType->ub - lastType->lb;