Fix some defects in the LDPC mod2 matrix free routines

Add  a function  to free  heap allocations  made reading  in the  LDPC
parity check and generator matrices.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6763 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

lib/ldpc/mod2dense.c

@@ -65,9 +65,11 @@ mod2dense *mod2dense_allocate
 void mod2dense_free
 ( mod2dense *m		/* Matrix to free */
 )
-{ free(m->bits);
-  free(m->col);
-  free(m);
+{ if (m)
+  { free(m->bits);
+    free(m->col);
+    free(m);
+  }
 }
 
 

lib/ldpc/mod2sparse.c

@@ -114,13 +114,17 @@ void mod2sparse_free
 { 
   mod2block *b;
 
-  free(m->rows);
-  free(m->cols);
+  if (m)
+  { free(m->rows);
+    free(m->cols);
 
-  while (m->blocks!=0)
-  { b = m->blocks;
-    m->blocks = b->next;
-    free(b);
+    while (m->blocks!=0)
+    { b = m->blocks;
+      m->blocks = b->next;
+      free(b);
+    }
+
+    free (m);
   }
 }
 
@@ -1186,7 +1190,7 @@ int mod2sparse_decomp
       cc2 = 0;
       for (j = 0; j<N; j++)
       { cc3 = mod2sparse_count_col(B,j);
-        if (cc3>k || cc3==k && cc>0)
+        if (cc3>k || (cc3==k && cc>0))
         { if (cc3==k) cc -= 1;
           for (;;)
           { f = mod2sparse_first_in_col(B,j);

lib/ldpc/rcode.c

@@ -199,11 +199,19 @@ garbled:
   exit(1);
 }
 
-// Fortran interface routine for WSJT-X
+// Fortran interface routines for WSJT-X
 void init_ldpc_ (char *pfile, char *gfile )
 {
-    char *pchk_file,*gen_file;
     read_pchk( pfile );
     read_gen( gfile, 0, 0 );
 }
 
+void fini_ldpc_ ()
+{
+  mod2dense_free (G);
+  mod2sparse_free (U);
+  mod2sparse_free (L);
+  free (cols);
+  free (rows);
+  mod2sparse_free (H);
+}