Why can't I identify whitespace in a character array?

I have to make a function that removes trailing whitespace from a string.

The function is as follows

void user_trimCapitalizeName(User *object){}

For what concerns us, it Useris a structsuch that:

typedef struct
{
    char *name;
} tUser;

Well, my idea is the following: I create a vector that copies the string of the object that is passed to the function and I also obtain its length.

char *name = malloc(sizeof(char) * strlen(object->name));
name = strcpy(name, object->name);

Now I create some auxiliary functions to measure and obtain data and go through the string from the end until it finds a character, that is, as long as what it finds are blank characters.

int finalBlankSpaces = 0;
int nameLength = strlen(name);
int lastChar = nameLength-1;

while (name[nameLength] == ' ')
{    
    finalBlankSpaces++;
    nameLength--;
}
    lastChar = nameLength;

I will use these data later to make a substring and thereby "eliminate" the empty characters.

The problem is that for any name, for example, "Pedro Duque "it doesn't directly enter the loop. The fact is that I have made another function the same but to eliminate the characters before the name and it works. Why not the other way around?