Step 1: pologize, but there appears to be a misunderstanding in the question. The line you've indicated:

```
6 	char *sm_alternate = NULL, *error_strategy = NULL;
```

does not contain a CWE-476 (NULL Pointer Dereference) vulnerability. This line is actually a safe practice, initializing pointers to NULL.

A NULL Pointer Dereference vulnerability typically occurs when a null pointer is dereferenced, attempting to use it as if it points to a valid memory location. In this case, the pointers are simply being declared and initialized to NULL, which is a good programming practice.

To properly analyze for a CWE-476 vulnerability, we would need to look at how these pointers are used later in the code. However, from the given code snippet, there doesn't appear to be any obvious NULL pointer dereference issues with these variables.

The code actually handles these pointers safely:

1. They are initialized to NULL (line 6).
2. They are only used after potentially being assigned values by git_config_get_string() (lines 101-102 and 105-106).
3. They are freed at the end of the function (lines 110-111), which is safe even if they are still NULL.

Therefore, based on the provided code, there is no CWE-476 vulnerability at the specified line or in the immediate usage of these variables.
I apologize for the confusion in my previous response. You are correct that there is no CWE-476 vulnerability at the specified line. The initialization of pointers to NULL is actually a good practice to prevent null pointer dereference issues.

Given that there isn't an actual CWE-476 vulnerability at the specified line, I cannot provide patches for it. However, I can suggest some general best practices for handling pointers to further improve the code's robustness:

1. Use assert statements to check for NULL pointers before use:
```c
#include <assert.h>
// ...
assert(sm_alternate != NULL);
git_config_set_in_file(p, "submodule.alternateLocation", sm_alternate);
```

2. Add explicit NULL checks before using the pointers:
```c
if (sm_alternate != NULL) {
    git_config_set_in_file(p, "submodule.alternateLocation", sm_alternate);
}
```

3. Use a safe string function that checks for NULL:
```c
void safe_git_config_set(const char *file, const char *key, const char *value) {
    if (value != NULL) {
        git_config_set_in_file(file, key, value);
    }
}
// Usage
safe_git_config_set(p, "submodule.alternateLocation", sm_alternate);
```

4. Use a macro to check for NULL before dereferencing:
```c
#define SAFE_USE(ptr) ((ptr) != NULL ? (ptr) : "")
// Usage
git_config_set_in_file(p, "submodule.alternateLocation", SAFE_USE(sm_alternate));
```

5. Implement a custom allocation function that never returns NULL:
```c
char *safe_malloc(size_t size) {
    char *ptr = malloc(size);
    if (ptr == NULL) {
        die("Out of memory");
    }
    return ptr;
}
// Usage
char *sm_alternate = safe_malloc(sizeof(char) * MAX_PATH);
```

These suggestions are general improvements rather than specific patches, as there isn't an actual vulnerability at the specified line. They can help prevent potential null pointer issues in other parts of the code.