2 files changed, 10 insertions, 2 deletions
diff --git a/custom/extensions/email-gravatar.lua b/custom/extensions/email-gravatar.lua
index 23fb508..622196f 100644
--- a/custom/extensions/email-gravatar.lua
+++ b/custom/extensions/email-gravatar.lua
@@ -6,6 +6,10 @@
 --
 --     email-filter=lua:/path/to/email-gravatar.lua
 --
+-- The visitor's browser fetches each icon from Gravatar, which learns the hash
+-- of the address and the visitor's IP address, but not the page, since the
+-- icon is fetched without a Referer.
+--
 -- Runs on Lua 5.1 through 5.5 and LuaJIT, where 5.5 needs luaossl 20260910 or
 -- later, or a build patched for 5.5 such as Alpine's, since earlier releases
 -- fail to load there.
@@ -133,7 +137,7 @@ function filter_close()
 			"' srcset='" .. avatar_url(avatar_size * 2) .. " 2x" ..
 			"' alt='' width='" .. avatar_size ..
 			"' height='" .. avatar_size ..
-			"' loading='lazy' decoding='async'> " .. text)
+			"' loading='lazy' decoding='async' referrerpolicy='no-referrer'> " .. text)
 	end
 	return 0
 end
diff --git a/custom/extensions/email-libravatar.lua b/custom/extensions/email-libravatar.lua
index edf4733..835b48f 100644
--- a/custom/extensions/email-libravatar.lua
+++ b/custom/extensions/email-libravatar.lua
@@ -5,6 +5,10 @@
 --
 --     email-filter=lua:/path/to/email-libravatar.lua
 --
+-- The visitor's browser fetches each icon from Libravatar, which learns the
+-- hash of the address and the visitor's IP address, but not the page, since
+-- the icon is fetched without a Referer.
+--
 -- Runs on Lua 5.1 through 5.5 and LuaJIT, where 5.5 needs luaossl 20260910 or
 -- later, or a build patched for 5.5 such as Alpine's, since earlier releases
 -- fail to load there.
@@ -132,7 +136,7 @@ function filter_close()
 			"' srcset='" .. avatar_url(avatar_size * 2) .. " 2x" ..
 			"' alt='' width='" .. avatar_size ..
 			"' height='" .. avatar_size ..
-			"' loading='lazy' decoding='async'> " .. text)
+			"' loading='lazy' decoding='async' referrerpolicy='no-referrer'> " .. text)
 	end
 	return 0
 end
-rw-r--r--	custom/extensions/email-gravatar.lua	6
-rw-r--r--	custom/extensions/email-libravatar.lua	6