Add Regular style when no meta data available to guess a style

This makes sure that fullname can be constructed at least even if a style is missing
and "Regular" is omitted for fullname so this change won't affect in that case.

Fixes https://gitlab.freedesktop.org/fontconfig/fontconfig/-/issues/259
diff --git a/src/fcfreetype.c b/src/fcfreetype.c
index 0001f38..3bdf92b 100644
--- a/src/fcfreetype.c
+++ b/src/fcfreetype.c
@@ -1625,13 +1625,26 @@
 	++nfamily;
     }
 
-    if (!variable && !nstyle && face->style_name &&
-	FcStrCmpIgnoreBlanksAndCase ((FcChar8 *) face->style_name, (FcChar8 *) "") != 0)
+    if (!variable && !nstyle)
     {
-	if (FcDebug () & FC_DBG_SCANV)
-	    printf ("using FreeType style \"%s\"\n", face->style_name);
+	const FcChar8 *style_regular = (const FcChar8 *) "Regular";
+	const FcChar8 *ss;
 
-	if (!FcPatternObjectAddString (pat, FC_STYLE_OBJECT, (FcChar8 *) face->style_name))
+	if (face->style_name &&
+	    FcStrCmpIgnoreBlanksAndCase ((FcChar8 *) face->style_name, (FcChar8 *) "") != 0)
+	{
+	    if (FcDebug () & FC_DBG_SCANV)
+		printf ("using FreeType style \"%s\"\n", face->style_name);
+
+	    ss = (const FcChar8 *) face->style_name;
+	}
+	else
+	{
+	    if (FcDebug () & FC_DBG_SCANV)
+		printf ("applying default style Regular\n");
+	    ss = style_regular;
+	}
+	if (!FcPatternObjectAddString (pat, FC_STYLE_OBJECT, ss))
 	    goto bail1;
 	if (!FcPatternObjectAddString (pat, FC_STYLELANG_OBJECT, (FcChar8 *) "en"))
 	    goto bail1;