[PATCH 3/4] gitweb.cgi: Show "raw" head of project link even when $hash is not defined

Some callers of git_history() do not set $hash of $file_name.
Add code to find it, if it is not defined.

Signed-off-by: Luben Tuikov <redacted>
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 gitweb/gitweb.cgi |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)