merge-recursive: fix parsing of "diff-algorithm" option

The "diff-algorithm" option to the recursive merge strategy takes the
name of the algorithm as an option, but it uses strcmp on the option
string to check if it starts with "diff-algorithm=", meaning that this
options cannot actually be used.

Fix this by switching to prefixcmp.  At the same time, clarify the
following line by using strlen instead of a hard-coded length, which
also makes it consistent with nearby code.

Reported-by: Luke Noel-Storr <luke.noel-storr@integrate.co.uk>
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

0 files changed, 0 insertions, 0 deletions