BST node deletion in c - c

Question

i'm trying to delete the nodes of a BST of strings that don't have a certain char in a certain position, but the code seg-faults and i can't trace the source of the error.
the inserting phase does the job, it's the deleting part that gives me headaches.
the delete function finds the key in the tree then deletes the node containing that key.
any help?
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct BST {
char *value;
struct BST *p_left;
struct BST *p_right;
};
typedef int (*Compare)(const char *, const char *);
int CmpStr(const char *a, const char *b)
{return (strcmp (a, b));}
//function to insert words into string
void insertInTree(char* key, struct BST** leaf, Compare cmp) {
int res;
if( *leaf == NULL ) {
*leaf = (struct BST*) malloc(sizeof( struct BST ) );
(*leaf)->value = malloc( strlen (key) +1 );
strcpy ((*leaf)->value, key);
(*leaf)->p_left = NULL;
(*leaf)->p_right = NULL;
} else {
res = cmp (key, (*leaf)->value);
if( res < 0)
insertInTree(key, &(*leaf)->p_left, cmp);
else if( res > 0)
insertInTree(key, &(*leaf)->p_right, cmp);
}
}
//helper function to find the min value string in alphabetical order
char* minValueNode(struct BST* node) {
struct BST* current = node;
while (current->p_left != NULL)
current = current->p_left;
return current->value;
}
//function to delete the node in the BST
struct BST* deleteNode(struct BST* root, char *key) {
if (root == NULL)
return NULL;
int cmp_result = strcmp(key, root->value);
if (cmp_result < 0)
root->p_right= deleteNode(root->p_right, key);
else if (cmp_result>0)
root->p_left= deleteNode(root->p_left, key);
else{
if (root->p_left == NULL && root->p_right == NULL){
free(root);
return NULL;
}
else if (root->p_left==NULL) {
struct BST *temp = root->p_right;
free(root);
return temp;
} else if(root->p_right==NULL){
struct BST *temp = root->p_left;
free(root);
return temp;
}
else {
char *newMin = minValueNode(root->p_right);
strcpy(root->value, newMin);
root->p_right= deleteNode(root->p_right, newMin);
}
}
return root;
}
//function to check if there is the exactchar char in the n position in the string
void charInExactPosition(struct BST *head, char exactchar, int n)
{
if( head != NULL ) {
charInExactPosition(head->p_left, exactchar, n);
if (head->value[n]!=exactchar){
deleteNode(head, head->value);}
charInExactPosition(head->p_right, exactchar, n);
}
}
void printTree(struct BST *root)
{
if( root != NULL ) {
printTree(root->p_left);
printf("%s\n", root->value);
printTree(root->p_right);
}
}
int main(){
struct BST* tree = NULL;
insertInTree("AAAAA", &tree, (Compare) CmpStr);
insertInTree("AkdAA", &tree, (Compare) CmpStr);
insertInTree("AAfAA", &tree, (Compare) CmpStr);
insertInTree("AdgAA", &tree, (Compare) CmpStr);
insertInTree("AhAAA", &tree, (Compare) CmpStr);
insertInTree("AAAiA", &tree, (Compare) CmpStr);
insertInTree("2AAAA", &tree, (Compare) CmpStr);
charInExactPosition(tree, 'A', 1);
printTree(tree);
}