grep.8f08d8e2.diagnosis.txt

If grep is set to search for lines containing whole words that match a regular
expression (-w), it prints only the match instead of the complete line. When
execute searches for a match, it correctly sets variable len to the length of
the match (search.c:388). When it is checked if the match aligns with word
bounderies (search.c:408-414), the match length len still points to the end of
the match. So, execute returns the length of the match instead of the end of
the line (grep.c:997). 

Examples of Correct Fixes: 
1) Add statement: goto success (which updates len with end - beg). 
2) Update len with end - beg. 

Example of Incorrect Fix: 
Always return complete line (Regression because in some settings grep should
return only the match).