From 9ff27d27e08439b899268a024af6321a16213301 Mon Sep 17 00:00:00 2001
From: handa <handa>
Date: Tue, 14 Sep 2010 11:13:19 +0000
Subject: [PATCH] (ft_check_otf): Fix handling of negative features.

---
 src/font-ft.c |   73 ++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 49 insertions(+), 24 deletions(-)

diff --git a/src/font-ft.c b/src/font-ft.c
index dd62e6e..79d6bbe 100644
--- a/src/font-ft.c
+++ b/src/font-ft.c
@@ -2142,6 +2142,8 @@ ft_close (MRealizedFont *rfont)
   free (rfont);
 }
 
+/* See the comment of parse_otf_command (m17n-flt.c).  */
+
 static int 
 ft_check_otf (MFLTFont *font, MFLTOtfSpec *spec)
 {
@@ -2149,34 +2151,57 @@ ft_check_otf (MFLTFont *font, MFLTOtfSpec *spec)
   OTF_Tag *tags;
   int i, n, negative;
   OTF *otf = get_otf (font, NULL);
+  
+  if (spec->features[0] && spec->features[0][0] ==0
+      && spec->features[1] && spec->features[1][0] ==0)
+    /* Return 1 iff any of GSUB or GPOS support the script (and language).  */
+    return (otf
+	    && (OTF_check_features (otf, 0, spec->script, spec->langsys,
+				    NULL, 0) > 0
+		|| OTF_check_features (otf, 1, spec->script, spec->langsys,
+				       NULL, 0) > 0));
 
-  if (! otf)
-    goto not_otf;
   for (i = 0; i < 2; i++)
-    {
-      if (! spec->features[i])
-	continue;
-      for (n = 0; spec->features[i][n]; n++);
-      tags = alloca (sizeof (OTF_Tag) * n);
-      for (n = 0, negative = 0; spec->features[i][n]; n++)
-	{
-	  if (spec->features[i][n] == 0xFFFFFFFF)
-	    negative = 1;
-	  else if (negative)
-	    tags[n - 1] = spec->features[i][n] | 0x80000000;
-	  else
-	    tags[n] = spec->features[i][n];
-	}
-      if (n - negative > 0
-	  && OTF_check_features (otf, i == 0, spec->script, spec->langsys,
-				 tags, n - negative) != 1)
-	return 0;
-    }
+    if (! spec->features[i] || spec->features[i][0] != 0)
+      {
+	int no_feature = ! otf || OTF_get_features (otf, i == 0) < 0;
+
+	if (! spec->features[i])
+	  {
+	    if (no_feature)
+	      continue;
+	    return 0;
+	  }
+	if (spec->features[i][0] == 0xFFFFFFFF)
+	  {
+	    if (no_feature)
+	      continue;
+	  }
+	else if (no_feature)
+	  return 0;
+	/* Now (! no_feature) */
+	for (n = 1; spec->features[i][n]; n++);
+	tags = alloca (sizeof (OTF_Tag) * n);
+	for (n = 0, negative = 0; spec->features[i][n]; n++)
+	  {
+	    if (spec->features[i][n] == 0xFFFFFFFF)
+	      negative = 1;
+	    else if (negative)
+	      tags[n - 1] = spec->features[i][n] | 0x80000000;
+	    else
+	      tags[n] = spec->features[i][n];
+	  }
+	if (OTF_check_features (otf, i == 0, spec->script, spec->langsys,
+				tags, n - negative) != 1)
+	  return 0;
+      }
   return 1;
- not_otf:
+
 #endif	/* HAVE_OTF */
-  return ((! spec->features[0] || spec->features[0][0] == 0xFFFFFFFF)
-	  && (! spec->features[1] || spec->features[1][0] == 0xFFFFFFFF));
+  return ((! spec->features[0] || (spec->features[0][0] == 0
+				   && spec->features[0][0] == 0xFFFFFFFF))
+	  && (! spec->features[0] || (spec->features[0][0] == 0
+				      && spec->features[0][0] == 0xFFFFFFFF)));
 }
 
 #ifdef HAVE_OTF
-- 
1.7.10.4