malloc（）内存释放问题

[C_master_RT]

代码末尾对malloc（）分配的内存内存进行释放，但加上这段代码后编译会出错，不释放反而可以。不说说凡是有malloc（）都要free（）吗？

#include<stdio.h>
#include<string.h>
#include<stdlib.h>

#define TSIZE 45

struct film
{
	char title[TSIZE];
	int rating;
	struct film *next;     /*指向链表的下一个结构*/
};

int main(void)
{

	struct film * head = NULL;
	struct film * current, * prev;
	char input[TSIZE];

    /*收集并存储信息*/
	puts("enter the first movie title:");
	while (gets(input) != NULL && input[0] != '\0')
	{
		current = (struct film *)malloc(sizeof(struct film));
		if (head == NULL)    /*第一个结构*/
		{
			head = current;    
		}
		else                              /*后续结构*/
		{
			prev->next = current; 
		}
		current->next = NULL;
		strcpy(current->title, input);
		puts("enter the movie rating(0-10)");
		scanf("%d", ¤t->rating);
		while (getchar() != '\n')
		{
			continue;
		}
		puts("enter the next movie title(enter empty line to quit):");
		prev = current;
	}

    /*给出电影列表*/
	if (head == NULL)
	{
		puts("no date entered!");
	}
	else
	{
		printf("here is the movie list:");
	}
	current = head;
	while (current != NULL)
	{
		printf("Movie: %s rating: %d", current->title, current->rating);
		current = current->next;
	}

 /*释放分配的内存*/
    current = head;
	while (current != NULL)
	{
		free(current);
		current = current->next;
	}
	printf("Bye!");

	return 0;
}

[brookmill]

free(current); current = current->next; // 前面一行已经释放了current，那么这里就不能再使用current->next了 应该是这样： tmp = current->next; free(current); current = tmp;

[C_master_RT]

引用 1 楼 brookmill 的回复:

free(current); current = current->next; // 前面一行已经释放了current，那么这里就不能再使用current->next了 应该是这样： tmp = current->next; free(current); current = tmp;

非常感谢，完美的解决了问题