reduce verbosity of the font loader

this is my version of:

    https://github.com/phi-gamma/luaotfload/commit/3a59b8b6b226ed22ccd16aec2dc2e272f015cc74

I undid the original because our policy is not to change imported files
except for applying hot fixes in advance that Hans will add eventually.

However, we’ll see if we really need otfl-fonts.lua anyways as its
functionality might fit better in to luaotfload.lua.

1 files changed, 41 insertions, 0 deletions

diff --git a/luaotfload.lua b/luaotfload.lua
index c85041b..f11218e 100644
--- a/luaotfload.lua
+++ b/luaotfload.lua
@@ -16,6 +16,7 @@ local type, next       = type, next
 local stringfind       = string.find
 local stringsub        = string.sub
 local stringmatch      = string.match
+local stringformat     = string.format
 local find_file        = kpse.find_file
 
 local add_to_callback, create_callback =
@@ -170,6 +171,41 @@ _G.non_generic_context = { luatex_fonts = {
 }}
 
 --[[doc--
+In its raw form, the font loader will write to the terminal quite
+liberally, not using the proper channels (loggers) even of \CONTEXT.
+To make it behave we temporarily replace two functions from the
+\luafunction{texio} library with wrappers that redirect output to the
+log.
+Just in case Hans decides to call \luafunction{texio.write*} with the
+optional target parameter (which he doesn’t at the moment), we catch the
+first argument and skip it where appropriate.
+The originals are backed up and restored after loading
+\fileent{otfl-fonts.lua}.
+
+Should we decide to do our own packaging (we’re capable of that
+anyways), this will most likely become unnecessary.
+--doc]]--
+
+local normal_write, normal_write_nl = texio.write, texio.write_nl
+
+local log_template = "luaotfload: %s"
+local fake_write = function (first, rest)
+    if first == "log" or first == "term" then -- ignore
+        normal_write("log", stringformat(log_template, rest))
+    else
+        normal_write("log", stringformat(log_template, first))
+    end
+end
+local fake_write_nl = function (first, rest)
+    if first == "log" or first == "term" then -- ignore
+        normal_write_nl("log", stringformat(log_template, rest))
+    else
+        normal_write_nl("log", stringformat(log_template, first, rest))
+    end
+end
+texio.write, texio.write_nl = fake_write, fake_write_nl
+
+--[[doc--
 The imported font loader will call \luafunction{callback.register} once
 while reading \fileent{font-def.lua}.
 This is unavoidable unless we modify the imported files, but harmless
@@ -186,6 +222,11 @@ Now that things are sorted out we can finally load the fontloader.
 loadmodule"fonts.lua"
 
 --[[doc--
+Here we restore the original \luafunction{texio} functions.
+--doc]]--
+texio.write, texio.write_nl = normal_write, normal_write_nl
+
+--[[doc--
 By default, the fontloader requires a number of \emphasis{private
 attributes} for internal use.
 These must be kept consistent with the attribute handling methods as