Longest run of a character in a string Your challenge: Write a function that takes a string s, a character c, and finds the length of the longest run of c in s. The length of the run will be l.

Rules:


If s is of length 0 or c is empty, l should be 0.
If there are no instances of c in s, l should be 0.
Standard loopholes and Standard I/O Rules apply.
No matter where in s the run of cs is located, l should be the same.
Any printable ASCII characters can appear in s and c.


Test cases:

s,c --&gt; l
"Hello, World!",'l'  --&gt;  2
"Foobar",'o'         --&gt;  2
"abcdef",'e'         --&gt;  1
"three   spaces",' ' --&gt;  3
"xxx xxxx xx",'x'    --&gt;  4
"xxxx xx xxx",'x'    --&gt;  4
"",'a'               --&gt;  0
"anything",''        --&gt;  0


Winner:

As with code-golf the shortest answer in each language wins.
05AB1E, 5 bytes
Code:
SQγOM

Uses the 05AB1E encoding. Try it online!
Explanation:
SQ      # Check for each character if it is equal to the second input
  γ     # Split the list of zeros and ones into groups
   O    # Sum each array in the arrays
    M   # Get the maximum