1 file changed, 4 insertions, 3 deletions
diff --git a/custom/extensions/email-gravatar.lua b/custom/extensions/email-gravatar.lua
index 01db3f9..836841f 100644
--- a/custom/extensions/email-gravatar.lua
+++ b/custom/extensions/email-gravatar.lua
@@ -12,7 +12,8 @@
 -- The one dependency is luaossl, the OpenSSL binding that provides
 -- openssl.digest, from <https://github.com/wahern/luaossl>. The reliable
 -- cross-platform install is LuaRocks, matched to the Lua version cgit is built
--- against, and it needs the OpenSSL development headers present.
+-- against, and it needs the OpenSSL development headers present. Without it
+-- the filter draws no icons and leaves the names as they are.
 --
 --     # Debian and Ubuntu
 --     sudo apt install luarocks libssl-dev
@@ -31,7 +32,7 @@
 -- that is not acceptable for your instance. Addresses are hashed with MD5,
 -- which Gravatar still accepts.
 
-local digest = require("openssl.digest")
+local has_digest, digest = pcall(require, "openssl.digest")
 
 
 -- The size is in pixels and serves both as the image asked of the service
@@ -94,7 +95,7 @@ end
 function filter_open(email, page)
 	buffer = ""
 	local address = normalize_email(email)
-	if address == nil then
+	if address == nil or not has_digest then
 		avatar_hash = nil
 	else
 		avatar_hash = hash_hex(address)