drop scanning fonts.conf in favor of `fc-cat`

1 files changed, 45 insertions, 95 deletions

diff --git a/luaotfload-database.lua b/luaotfload-database.lua
index 4980766..e23902a 100644
--- a/luaotfload-database.lua
+++ b/luaotfload-database.lua
@@ -21,6 +21,7 @@ local tonumber                = tonumber
 local fontloaderinfo          = fontloader.info
 local iolines                 = io.lines
 local ioopen                  = io.open
+local iopopen                 = io.popen
 local kpseexpand_path         = kpse.expand_path
 local kpseexpand_var          = kpse.expand_var
 local kpselookup              = kpse.lookup
@@ -234,7 +235,6 @@ local find_closest
 local flush_cache
 local font_fullinfo
 local load_names
-local read_fonts_conf
 local reload_db
 local resolve
 local save_names
@@ -1141,6 +1141,29 @@ local function scan_texmf_fonts(fontnames, newfontnames)
     return n_scanned, n_new
 end
 
+--- fc-cat outputs every directory it finds fonts in,
+--- so we have to remove all subdirectories from the
+--- list.
+
+--- dir list -> dir list
+local collapse_paths = function (dir_lst)
+    tablesort(dir_lst)
+    local last  = dir_lst[1]
+    local res   = { last }
+    local ndirs = #dir_lst
+    if ndirs > 1 then
+        for i=2, ndirs do
+            local dir = dir_lst[i]
+            if stringsub(dir, 1, #last) ~= last then
+                --- new prefix
+                res[#res+1] = dir
+                last = dir
+            end
+        end
+    end
+    return res
+end
+
 --[[
   For the OS fonts, there are several options:
    - if OSFONTDIR is set (which is the case under windows by default but
@@ -1148,99 +1171,32 @@ end
      in the scan_texmf_fonts.
    - if not:
      - under Windows and Mac OSX, we take a look at some hardcoded directories
-     - under Unix, we read /etc/fonts/fonts.conf and read the directories in it
+     - under Unix, we parse the output of “fc-cat -v”
 
   This means that if you have fonts in fancy directories, you need to set them
   in OSFONTDIR.
 ]]
 
---- (string -> tab -> tab -> tab)
-read_fonts_conf = function (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.
-
-    TODO    fonts.conf are some kind of XML so in theory the following
-            is totally inappropriate. Maybe a future version of the
-            lualibs will include the lxml-* files from Context so we
-            can write something presentable instead.
-    ]]
-    local fh = ioopen(path)
-    passed_paths[#passed_paths+1] = path
-    passed_paths_set = tabletohash(passed_paths, true)
-    if not fh then
-        report("log", 2, "db", "cannot open file %s", path)
-        return results
-    end
-    local incomments = false
-    for line in fh:lines() do
-        while line and line ~= "" do
-            -- spaghetti code... hmmm...
-            if incomments then
-                local tmp = stringfind(line, '-->') --- wtf?
-                if tmp then
-                    incomments = false
-                    line = stringsub(line, tmp+3)
-                else
-                    line = nil
-                end
-            else
-                local tmp = stringfind(line, '<!--')
-                local newline = line
-                if tmp then
-                    -- for the analysis, we take everything that is before the
-                    -- comment sign
-                    newline = stringsub(line, 1, tmp-1)
-                    -- and we loop again with the comment
-                    incomments = true
-                    line = stringsub(line, tmp+4)
-                else
-                    -- if there is no comment start, the block after that will
-                    -- end the analysis, we exit the while loop
-                    line = nil
-                end
-                for dir in stringgmatch(newline, '<dir>([^<]+)</dir>') do
-                    -- now we need to replace ~ by kpse.expand_path('~')
-                    if stringsub(dir, 1, 1) == '~' then
-                        dir = filejoin(kpseexpand_path('~'), stringsub(dir, 2))
-                    end
-                    -- we exclude paths with texmf in them, as they should be
-                    -- found anyway
-                    if not stringfind(dir, 'texmf') then
-                        results[#results+1] = dir
-                    end
-                end
-                for include in stringgmatch(newline, '<include[^<]*>([^<]+)</include>') do
-                    -- include here can be four things: a directory or a file,
-                    -- in absolute or relative path.
-                    if stringsub(include, 1, 1) == '~' then
-                        include = filejoin(kpseexpand_path('~'),stringsub(include, 2))
-                        -- First if the path is relative, we make it absolute:
-                    elseif not lfs.isfile(include) and not lfs.isdir(include) then
-                        include = filejoin(file.dirname(path), include)
-                    end
-                    if      lfs.isfile(include)
-                    and     kpsereadable_file(include)
-                    and not passed_paths_set[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, passed_paths)
-                    elseif lfs.isdir(include) then
-                        for _,f in next, dirglob(filejoin(include, "*.conf")) do
-                            if not passed_paths_set[f] then
-                                read_fonts_conf(f, results, passed_paths)
-                            end
-                        end
-                    end
-                end
-            end
+--[[doc--
+Instead of processing the fontconfig configuration files with a
+haphazarad XML parser, we scan the output of fc-cache for search paths
+and use these. This way we don’t need to resolve possible included
+files.
+--doc]]--
+local get_fontconfig_paths = function ( )
+    local fc_cat_cmd = "fc-cat -v 2> /dev/null"
+    local res = { }
+    local chan = assert(iopopen(fc_cat_cmd, "r"),
+                        "cannot read from pipe")
+    local nlines = 0
+    for line in chan:lines() do
+        nlines = nlines + 1
+        if stringsub(line, 1, 11) == "Directory: " then
+            res[#res+1] = string.explode(line, " ")[2] .. "/"
         end
     end
-    fh:close()
-    return results
+    chan:close()
+    return collapse_paths(res)
 end
 
 -- for testing purpose
@@ -1259,13 +1215,7 @@ local function get_os_dirs()
         local windir = os.getenv("WINDIR")
         return { filejoin(windir, 'Fonts') }
     else 
-        local passed_paths = {}
-        local os_dirs = {}
-        for _,p in next, {"/usr/local/etc/fonts/fonts.conf", "/etc/fonts/fonts.conf"} do
-            if lfs.isfile(p) then
-                read_fonts_conf(p, os_dirs, passed_paths)
-            end
-        end
+        local os_dirs = get_fontconfig_paths()
         return os_dirs
     end
     return {}
@@ -1275,7 +1225,7 @@ local function scan_os_fonts(fontnames, newfontnames)
     local n_scanned, n_new = 0, 0
     --[[
     This function scans the OS fonts through
-      - fontcache for Unix (reads the fonts.conf file and scans the directories)
+      - fontcache for Unix (runs fc-cat -v and scans the directories)
       - a static set of directories for Windows and MacOSX
     ]]
     report("info", 2, "db", "Scanning OS fonts...")