composetable: Warn for things we can't handle

The compose table stores the keyvals to match against
in a guint16 array, so it can't handle directly encoded
Unicode codepoints (which have a high bit set). Warn
if we encounter those.

gtk/gtkcomposetable.c

@@ -231,7 +231,7 @@ parse_compose_sequence (const char *seq,
       char *start = words[i];
       char *end = strchr (words[i], '>');
       char *match;
-      gunichar codepoint;
+      guint keyval;
 
       if (words[i][0] == '\0')
              continue;
@@ -248,18 +248,24 @@ parse_compose_sequence (const char *seq,
 
       if (is_codepoint (match))
         {
-          codepoint = (gunichar) g_ascii_strtoll (match + 1, NULL, 16);
-          sequence[n] = codepoint;
+          keyval = gdk_unicode_to_keyval ((gunichar) g_ascii_strtoll (match + 1, NULL, 16));
+          if (keyval > 0xffff)
+            g_warning ("Can't handle >16bit keyvals");
+
+          sequence[n] = (guint16) keyval;
           sequence[n + 1] = 0;
         }
       else
         {
-          codepoint = (gunichar) gdk_keyval_from_name (match);
-          sequence[n] = codepoint;
+          keyval = gdk_keyval_from_name (match);
+          if (keyval > 0xffff)
+            g_warning ("Can't handle >16bit keyvals");
+
+          sequence[n] = (guint16) keyval;
           sequence[n + 1] = 0;
         }
 
-      if (codepoint == GDK_KEY_VoidSymbol)
+      if (keyval == GDK_KEY_VoidSymbol)
         g_warning ("Could not get code point of keysym %s", match);
       g_free (match);
       n++;

testsuite/gtk/compose/match

@@ -2,3 +2,5 @@
 <Multi_key> <s> <e> <q> <u> : "?"
 <Multi_key> <z> <w> <i> <n> <e> <s> : "🥂"
 <Multi_key> <l> <o> <n> <g> : "this is a long replacement string"
+<q> : "qq"
+<UFEF7>	: "foobar"

testsuite/gtk/composetable.c

@@ -242,6 +242,26 @@ compose_table_match (void)
   g_assert_true (match);
   g_assert_cmpstr (output->str, ==, "this is a long replacement string");
 
+  g_string_set_size (output, 0);
+
+  buffer[0] = GDK_KEY_q;
+  buffer[1] = 0;
+  ret = gtk_compose_table_check (table, buffer, 1, &finish, &match, output);
+  g_assert_true (ret);
+  g_assert_false (finish);
+  g_assert_true (match);
+  g_assert_cmpstr (output->str, ==, "qq");
+
+  g_string_set_size (output, 0);
+
+  buffer[0] = 0x0100FEF7;
+  buffer[1] = 0;
+  ret = gtk_compose_table_check (table, buffer, 1, &finish, &match, output);
+  g_assert_true (ret);
+  g_assert_false (finish);
+  g_assert_true (match);
+  g_assert_cmpstr (output->str, ==, "foobar");
+
   g_string_free (output, TRUE);
   g_free (file);
 }