fix some compiler warnings

Author: jcupitt

src/heap.c

@@ -778,7 +778,7 @@ heap_getmem( Heap *heap )
 	 * it here as well just in case.
 	 */
 	if( heap->free ) {
-		EXTRACTNODE( heap, hn );
+		(void) EXTRACTNODE( heap, hn );
 		return( hn );
 	}
 
@@ -830,7 +830,7 @@ heap_getmem( Heap *heap )
 		return( NULL );
 	}
 
-	EXTRACTNODE( heap, hn );
+	(void) EXTRACTNODE( heap, hn );
 
 	return( hn );
 }

src/heap.h

@@ -336,20 +336,20 @@ typedef struct _HeapClass {
  * pointer in node to heap sym pointer.
  */
 #ifdef DEBUG_HEAP
-#define EXTRACTNODE(H,A) \
-	(heap_sanity(H),(A)=(H)->free,(H)->free=GETLEFT(A),0)
+#define EXTRACTNODE( H, A ) \
+	(heap_sanity( H ), (A) = (H)->free, (H)->free = GETLEFT( A ), 0)
 #else /*!DEBUG_HEAP*/
-#define EXTRACTNODE(H,A) \
-	((A)=(H)->free,(H)->free=GETLEFT(A),0)
+#define EXTRACTNODE( H, A ) \
+	((A) = (H)->free, (H)->free = GETLEFT( A ), 0)
 #endif /*DEBUG_HEAP*/
 
 /* Allocate a new node from heap H, pop the pointer into A, return non-zero if
  * alloc failed. Node is uninitialised!
  */
-#define NEWNODE(H,A) ( \
-	(H)->free ?\
-		EXTRACTNODE(H,A):\
-		(((A)=heap_getmem(H)) ? 0 : -1)\
+#define NEWNODE( H, A ) ( \
+	(H)->free ? \
+		EXTRACTNODE( H, A ): \
+		(((A) = heap_getmem( H )) ? 0 : -1) \
 	)
 
 typedef void *(*heap_safe_pointer_fn)( Heap *heap, PElement *, 

src/matrixview.c

@@ -494,6 +494,10 @@ matrixview_text_build( Matrixview *matrixview )
 	gtk_tree_view_set_headers_visible( GTK_TREE_VIEW( matrixview->sheet ),
 		FALSE );
 
+	/* Stops a harmless compiler warning.
+	 */
+	column = NULL;
+
 	for( i = 0; i < matrix->value.width; i++ ) {
 		GtkCellRenderer *renderer;
 		char buf[256];