math/gfreduce.[ch]: Fix out-of-bounds memory access.

[u/mdw/catacomb] / math / mpreduce.h

diff --git a/math/mpreduce.h b/math/mpreduce.h
index c90c93f..efac88f 100644 (file)
--- a/math/mpreduce.h
+++ b/math/mpreduce.h
@@ -34,6 +34,12 @@
 
 /*----- Header files ------------------------------------------------------*/
 
+#include <stdio.h>
+
+#ifndef CATACOMB_MP_H
+#  include "mp.h"
+#endif
+
 /*----- Data structures ---------------------------------------------------*/
 
 typedef struct mpreduce_instr {
@@ -64,7 +70,10 @@ typedef struct mpreduce {
  * Arguments:  @gfreduce *r@ = structure to fill in
  *             @mp *x@ = an integer
  *
- * Returns:    Zero for success, nonzero on error.
+ * Returns:    Zero if successful; nonzero on failure.  The current
+ *             algorithm always succeeds when given positive @x@.  Earlier
+ *             versions used to fail on particular kinds of integers, but
+ *             this is guaranteed not to happen any more.
  *
  * Use:                Initializes a context structure for reduction.
  */