From 6fdeeb2ae3059ac1bc5ff99fd1655b4e94576151 Mon Sep 17 00:00:00 2001
From: Khaled Hosny <khaledhosny@eglug.org>
Date: Thu, 19 Apr 2018 23:41:37 +0300
Subject: [PATCH] [util] Check all specified shapers are known (#993)

A bit brute force and requires all shapers to be known, not just one.

Fixes https://github.com/harfbuzz/harfbuzz/issues/956
---
 util/options.cc | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/util/options.cc b/util/options.cc
index c625d6573..aad843c2e 100644
--- a/util/options.cc
+++ b/util/options.cc
@@ -192,11 +192,29 @@ static gboolean
 parse_shapers (const char *name G_GNUC_UNUSED,
 	       const char *arg,
 	       gpointer    data,
-	       GError    **error G_GNUC_UNUSED)
+	       GError    **error)
 {
   shape_options_t *shape_opts = (shape_options_t *) data;
+  char **shapers = g_strsplit (arg, ",", 0);
+
+  for (char **shaper = shapers; *shaper; shaper++) {
+    bool found = false;
+    for (const char **hb_shaper = hb_shape_list_shapers (); *hb_shaper; hb_shaper++) {
+      if (strcmp (*shaper, *hb_shaper) == 0) {
+        found = true;
+        break;
+      }
+    }
+    if (!found) {
+      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
+		   "Unknown or unsupported shaper: %s", *shaper);
+      g_strfreev (shapers);
+      return false;
+    }
+  }
+
   g_strfreev (shape_opts->shapers);
-  shape_opts->shapers = g_strsplit (arg, ",", 0);
+  shape_opts->shapers = shapers;
   return true;
 }