A peculiar bug while reading and printing strings of *char in C - c

Question

I've just encountered something really odd. My string of char (let's call it word) turns out to have additional letters when I print it. The contatenated letter varies depending on:
the length of the proper prefix word.
the number of spaces after the word.
I'm parsing the word from a line which is just a one line form the standard input. I'm using a function readWord to get the word out of the line:
void readWord(char **linePointer, char **wordPointer){
char *line = *linePointer;
char *word = *wordPointer;
while (!isEndOfLine(line) && isLowerCaseLetter(*line)){
*word = *line;
word++;
line++;
}
word++;
*word = '\0';
printf("The retrieved word is: %s.\n", *wordPointer)
*linePointer = line;
}
My inputs/outputs look like this (please note that I call the readWord function AFTER taking care of insert and the whitespace between):
// INPUT 1 :
insert foo
insert ba // several spaces after 'ba'
// OUTPUT 2:
The retrieved word is foo.
The retrieved word is bas.
// INPUT 1 :
insert foo
insert ba // several spaces after 'bar'
// OUTPUT 2:
The retrieved word is foo.
The retrieved word is bare.
I was thinking whether I allocate the *word properly and I guess I do:
root.word = (char *)malloc(sizeof(char *)); //root is my structure
Moreover, it is unlikely connected to some errors of reassigning the word string because it is completely clear at the beginning of the readWord() function.
Thank you for any help. It is indeed a challenging bug for me and I don't know what else I can do.
UPDATE
It turns out that I actually have some problems with allocating/reassigning, since:
//INPUT
insert foo//no spaces
insert bar //spaces here
//OUTPUT
word variable before calling readWord function: ' '.
The retrieved word is foo.
word variable before calling readWord function: 'insert foo
'.
The retrieved word is bare.

Answer 1

Never trust your input, so check for spaces to go to the beginning of the word.
You increment word one too many, as #rpattiso notes.
I have doubts about your memory allocation (you don't show us all your code):
root.word = (char *)malloc(sizeof(char *)); allocates room for a pointer to a char, but does not allocate the room for the characters themselves. readWord can do that.
The following adapted version should work (updated):
void readWord(char **linePointer, char **wordPointer){
char *line = *linePointer;
int i;
while (!isEndOfLine(line) && !isLowerCaseLetter(*line)) line++; // go to begin of word
*linePointer= line;
while (!isEndOfLine(line) && isLowerCaseLetter(*line)) line++; // go to end of word
i= line - *linePointer; // allocate room for word and copy it
*wordPointer= malloc((i+1) * sizeof(char));
strncpy(*wordPointer, *linePointer, i);
(*wordPointer)[i]= '\0;
printf("The retrieved word is: %s.\n", *wordPointer);
*linePointer = line;
}