Preventing loop-references in fontconfig files

I just had this case on a recent Ubuntu...

1 files changed, 6 insertions, 5 deletions

diff --git a/otfl-font-nms.lua b/otfl-font-nms.lua
index e6faeab..0f44eb4 100644
--- a/otfl-font-nms.lua
+++ b/otfl-font-nms.lua
@@ -518,12 +518,13 @@ end
   in OSFONTDIR.
 ]]
 
-local function read_fonts_conf(path, results)
+local function read_fonts_conf(path, results, passed_paths)
     --[[
     This function parses /etc/fonts/fonts.conf and returns all the dir it finds.
     The code is minimal, please report any error it may generate.
     ]]
     local f = io.open(path)
+    table.insert(passed_paths, path)
     if not f then
         logs.info("Warning: unable to read "..path.. ", skipping...")
         return results
@@ -575,14 +576,14 @@ local function read_fonts_conf(path, results)
                     elseif not lfs.isfile(include) and not lfs.isdir(include) then
                         include = file.join(file.dirname(path), include)
                     end
-                    if lfs.isfile(include) and kpse.readable_file(include) then
+                    if lfs.isfile(include) and kpse.readable_file(include) and not table.contains(passed_paths, include) then
                         -- maybe we should prevent loops here?
                         -- we exclude path with texmf in them, as they should
                         -- be found otherwise
-                        read_fonts_conf(include, results)
+                        read_fonts_conf(include, results, passed_paths)
                     elseif lfs.isdir(include) then
                         for _,f in next, glob(file.join(include, "*.conf")) do
-                            read_fonts_conf(f, results)
+                            read_fonts_conf(f, results, passed_paths)
                         end
                     end
                 end
@@ -608,7 +609,7 @@ local function get_os_dirs()
         local windir = os.getenv("WINDIR")
         return { file.join(windir, 'Fonts') }
     else
-        return read_fonts_conf("/etc/fonts/fonts.conf", {})
+        return read_fonts_conf("/etc/fonts/fonts.conf", {}, {})
     end
 end