Thread: I think i found a bug

So i wrote a very simple program which includes a linked list,
the nodes within the list are dynamically allocated using malloc(), the program had 2 functions, add a new node to the list and print the nodes in the list.
Every time i added more than 2 nodes to the list(including the start node) and used the print function the program crashed.
With some if and print statements i found that the third (or which ever was last) node's *next was not NULL even though obviously it was not pointing at anything since it was the last node in the list.
The program crashed because there is a while loop that depended on that pointer being NULL to stop.

Anyway, changing the size of the array to 12 fixed the problem.
My question is why? I included the entire program if your interested
but it's kinda messy.

Code:

typedef struct example{
    
    char array[52];
    struct example *next;

}typeExample;

Code:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
//http://cboard.cprogramming.com/c-programming/167968-please-need-help-linked-list.html#post1239483
typedef struct LSexample{
    
    char name[12]; // name was too big that was the problem
    float decimals;
    struct LSexample *forward;
}typeLS;

typeLS *returnPointerToAllocatedMemory(typeLS *MainPointers){
    char UserInput5[16];
    fgets(UserInput5, 15,stdin);
    typeLS *PointertoAllocatedMemory = malloc(sizeof(typeLS));

    sscanf(UserInput5,"%s %f",PointertoAllocatedMemory->name,&PointertoAllocatedMemory->decimals );

    printf("Name:%s float:%f\n",PointertoAllocatedMemory->name,PointertoAllocatedMemory->decimals);
    if(MainPointers != NULL){//if there is somethign behind then set
                                //    whats behind pointer to point at the newly created structure 
        MainPointers->forward = PointertoAllocatedMemory;//mainpointers is the previous structure
                                                        // if there isn't one it will be NULL
    }
    return PointertoAllocatedMemory;
}
void cleanUp(typeLS *FirstStructure1){
    
    
    typeLS *freeThisAllocatedMemory = NULL;
    typeLS *HoldPointerForward = NULL;
    freeThisAllocatedMemory = FirstStructure1;
    
    while(freeThisAllocatedMemory != NULL){// if ? REALLY? LOOOOOOOL
        printf("Free name:%s float %f\n",freeThisAllocatedMemory->name,freeThisAllocatedMemory->decimals);
        HoldPointerForward = freeThisAllocatedMemory->forward; //if ->forward was bellow
        free(freeThisAllocatedMemory); //remember its cleaning the pointer not the struct
        freeThisAllocatedMemory = HoldPointerForward; //i mean here, then the cleaned pointer woudl get dirty again

    }
}
void printfunc(typeLS *FSpointer){
    
    typeLS *holder3 = FSpointer;
    
    while(holder3 != NULL){

        printf("name:%s float:%f\n",holder3->name,holder3->decimals);
        
        holder3 = holder3->forward;
        if(holder3 != NULL){

        }
    }

    
}


int main(){
    typeLS *Firststructure = NULL;//this pointer will point at the first structure in the list 
                                    
    typeLS *holderr = NULL; //this pointer will point at multiple things which is the trick of this logic
    char UserInput[16];
    char translation[16];
    while(fgets(UserInput, 15,stdin)){
        sscanf(UserInput,"%s",translation);
        if(strncmp(translation, "add",3)==0){

            if(Firststructure == NULL){
                Firststructure = returnPointerToAllocatedMemory(NULL);
                holderr = Firststructure;
            }else{
                holderr = returnPointerToAllocatedMemory(holderr);
            }
        }else if(strncmp(translation, "print",5)==0){
            printf("Printing...\n");
            printfunc(Firststructure);
        }else if(strncmp(translation, "quit",4)==0){
            printf("Breaking...\n");
            break;
        }
    }
    cleanUp(Firststructure);
    return 0;
}