filter: allow returning exit code from filter

Filters can now indicate a status back to cgit by means of the exit code
for exec, or the return value from close for Lua.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/filters/email-gravatar.lua b/filters/email-gravatar.lua
index 22f0641..c80b63e 100644
--- a/filters/email-gravatar.lua
+++ b/filters/email-gravatar.lua
@@ -16,6 +16,7 @@ end
 
 function filter_close()
 	html("<img src='//www.gravatar.com/avatar/" .. md5 .. "?s=13&amp;d=retro' style='height:10pt;width:10pt' alt='Gravatar' /> " .. buffer)
+	return 0
 end
 
 function filter_write(str)