1 files changed, 13 insertions, 10 deletions

diff --git a/stack2.c b/stack2.c
index 57dce4f..4c77ac2 100644
--- a/stack2.c
+++ b/stack2.c
@@ -1,13 +1,13 @@
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <stdbool.h>
 
 #include "util.h"
 
 typedef int T;
 
 struct stack {
-        T *array;
+        T *    array;
         size_t sz, p;
 };
 
@@ -15,8 +15,8 @@ void
 stack_init(struct stack *stack)
 {
         stack->array = NULL;
-        stack->sz = 0;
-        stack->p = 0;
+        stack->sz    = 0;
+        stack->p     = 0;
 }
 
 bool
@@ -25,7 +25,7 @@ stack_push(struct stack *stack, T data)
         if ( stack->array == NULL ) {
                 if ( (stack->array = malloc(10 * sizeof(*stack->array))) != NULL ) {
                         stack->sz = 10;
-                        stack->p = 0;
+                        stack->p  = 0;
                 }
                 else {
                         ERROR("out of memory");
@@ -35,11 +35,11 @@ stack_push(struct stack *stack, T data)
 
         if ( stack->p == stack->sz ) {
                 size_t new_sz;
-                T *new_array;
+                T *    new_array;
 
-                if ( (new_array = realloc(stack->array, (new_sz = (stack->sz * 3 / 2)) * sizeof(*stack->array))) != NULL ) {
+                if ( (new_array = realloc(stack->array, (new_sz = (stack->sz * 3 / 2)) * sizeof(*stack->array))) != NULL ) {
                         stack->array = new_array;
-                        stack->sz = new_sz;
+                        stack->sz    = new_sz;
                 }
                 else {
                         ERROR("out of memory");
@@ -55,7 +55,11 @@ bool
 stack_pop(struct stack *stack, T *data)
 {
         if ( stack->p != 0 ) {
-                *data = stack->array[--stack->p];
+                --stack->p;
+
+                if ( data != NULL ) {
+                        *data = stack->array[stack->p];
+                }
                 return true;
         }
         else
@@ -97,4 +101,3 @@ main()
 
         return EXIT_SUCCESS;
 }
-