I changed FcFontSetSort to respect the generic aliases better in the face

of language matching.
What I did was to ammend the strict sort order used by FcFontSort so that
    it 'satisfies' the language specified in the pattern by locating the
    best matching font supporting each pattern language and then ignores
    language in the remaining fonts for purposes of matching.
So, when asking for 'sans:lang=en', you'll get an English font first, and
    then the remaining fonts sorted with respect to the 'sans' alias alone
    -- pushing Kochi fonts ahead of other English-supporting Han fonts.
reviewed by: Owen Taylor <otaylor@redhat.com>

ChangeLog

@@ -1,3 +1,20 @@
+2004-12-13  Keith Packard  <keithp@keithp.com>
+
+	reviewed by: Owen Taylor <otaylor@redhat.com>
+
+	* src/fcmatch.c: (FcFontSetSort):
+	I changed FcFontSetSort to respect the generic aliases better
+	in the face of language matching.
+	
+	What I did was to ammend the strict sort order used by FcFontSort so
+	that it 'satisfies' the language specified in the pattern by locating
+	the best matching font supporting each pattern language and then
+	ignores language in the remaining fonts for purposes of matching.
+
+	So, when asking for 'sans:lang=en', you'll get an English font first,
+	and then the remaining fonts sorted with respect to the 'sans' alias
+	alone -- pushing Kochi fonts ahead of other English-supporting Han fonts.
+
 2004-12-10  Jakub Pavelek <jakub.pavelek@nokia.com>
 
 	reviewed by: Keith Packard  <keithp@keithp.com>

src/fcmatch.c

@@ -181,45 +181,60 @@ typedef struct _FcMatcher {
 static FcMatcher _FcMatchers [] = {
     { FC_FOUNDRY,	FcCompareString,	0, 0 },
 #define MATCH_FOUNDRY	    0
+#define MATCH_FOUNDRY_INDEX 0
     
     { FC_CHARSET,	FcCompareCharSet,	1, 1 },
 #define MATCH_CHARSET	    1
+#define MATCH_CHARSET_INDEX 1
     
     { FC_FAMILY,    	FcCompareFamily,	2, 4 },
 #define MATCH_FAMILY	    2
+#define MATCH_FAMILY_STRONG_INDEX   2
+#define MATCH_FAMILY_WEAK_INDEX	    4
     
     { FC_LANG,		FcCompareLang,		3, 3 },
 #define MATCH_LANG	    3
+#define MATCH_LANG_INDEX    3
     
     { FC_SPACING,	FcCompareNumber,	5, 5 },
 #define MATCH_SPACING	    4
+#define MATCH_SPACING_INDEX 5
     
     { FC_PIXEL_SIZE,	FcCompareSize,		6, 6 },
 #define MATCH_PIXEL_SIZE    5
+#define MATCH_PIXEL_SIZE_INDEX	6
     
     { FC_STYLE,		FcCompareString,	7, 7 },
 #define MATCH_STYLE	    6
+#define MATCH_STYLE_INDEX   7
     
     { FC_SLANT,		FcCompareNumber,	8, 8 },
 #define MATCH_SLANT	    7
+#define MATCH_SLANT_INDEX   8
     
     { FC_WEIGHT,	FcCompareNumber,	9, 9 },
 #define MATCH_WEIGHT	    8
+#define MATCH_WEIGHT_INDEX  9
     
     { FC_WIDTH,		FcCompareNumber,	10, 10 },
 #define MATCH_WIDTH	    9
+#define MATCH_WIDTH_INDEX   10
     
     { FC_ANTIALIAS,	FcCompareBool,		11, 11 },
 #define MATCH_ANTIALIAS	    10
+#define MATCH_ANTIALIAS_INDEX	    11
     
     { FC_RASTERIZER,	FcCompareString,	12, 12 },
 #define MATCH_RASTERIZER    11
-    
+#define MATCH_RASTERIZER_INDEX    12
+
     { FC_OUTLINE,	FcCompareBool,		13, 13 },
 #define MATCH_OUTLINE	    12
+#define MATCH_OUTLINE_INDEX	    13
 
     { FC_FONTVERSION,	FcCompareNumber,	14, 14 },
 #define MATCH_FONTVERSION   13
+#define MATCH_FONTVERSION_INDEX   14
 };
 
 #define NUM_MATCH_VALUES    15
@@ -663,6 +678,9 @@ FcFontSetSort (FcConfig	    *config,
     int		    set;
     int		    f;
     int		    i;
+    int		    nPatternLang;
+    FcBool    	    *patternLangSat;
+    FcValue	    patternLang;
 
     if (FcDebug () & FC_DBG_MATCH)
     {
@@ -679,11 +697,20 @@ FcFontSetSort (FcConfig	    *config,
     }
     if (!nnodes)
 	goto bail0;
+    
+    for (nPatternLang = 0;
+	 FcPatternGet (p, FC_LANG, nPatternLang, &patternLang) == FcResultMatch;
+	 nPatternLang++)
+	;
+	
     /* freed below */
-    nodes = malloc (nnodes * sizeof (FcSortNode) + nnodes * sizeof (FcSortNode *));
+    nodes = malloc (nnodes * sizeof (FcSortNode) + 
+		    nnodes * sizeof (FcSortNode *) +
+		    nPatternLang * sizeof (FcBool));
     if (!nodes)
 	goto bail0;
     nodeps = (FcSortNode **) (nodes + nnodes);
+    patternLangSat = (FcBool *) (nodeps + nnodes);
     
     new = nodes;
     nodep = nodeps;
@@ -721,6 +748,56 @@ FcFontSetSort (FcConfig	    *config,
     
     qsort (nodeps, nnodes, sizeof (FcSortNode *),
 	   FcSortCompare);
+    
+    for (i = 0; i < nPatternLang; i++)
+	patternLangSat[i] = FcFalse;
+    
+    for (f = 0; f < nnodes; f++)
+    {
+	FcBool	satisfies = FcFalse;
+	/*
+	 * If this node matches any language, go check
+	 * which ones and satisfy those entries
+	 */
+	if (nodeps[f]->score[MATCH_LANG_INDEX] < nPatternLang)
+	{
+	    for (i = 0; i < nPatternLang; i++)
+	    {
+		FcValue	    nodeLang;
+		
+		if (!patternLangSat[i] &&
+		    FcPatternGet (p, FC_LANG, i, &patternLang) == FcResultMatch &&
+		    FcPatternGet (nodeps[f]->pattern, FC_LANG, 0, &nodeLang) == FcResultMatch)
+		{
+		    double  compare = FcCompareLang (FC_LANG, patternLang, 
+						     nodeLang);
+		    if (compare >= 0 && compare < 2)
+		    {
+			if (FcDebug () & FC_DBG_MATCHV)
+			{
+			    FcChar8 *family;
+			    FcChar8 *style;
+
+			    if (FcPatternGetString (nodeps[f]->pattern, FC_FAMILY, 0, &family) == FcResultMatch &&
+				FcPatternGetString (nodeps[f]->pattern, FC_STYLE, 0, &style) == FcResultMatch)
+				printf ("Font %s:%s matches language %d\n", family, style, i);
+			}
+			patternLangSat[i] = FcTrue;
+			satisfies = FcTrue;
+			break;
+		    }
+		}
+	    }
+	}
+	if (!satisfies)
+	    nodeps[f]->score[MATCH_LANG_INDEX] = 1000.0;
+    }
+
+    /*
+     * Re-sort once the language issues have been settled
+     */
+    qsort (nodeps, nnodes, sizeof (FcSortNode *),
+	   FcSortCompare);
 
     ret = FcFontSetCreate ();
     if (!ret)