Add a check for mixed linkageprevent-mixed-linkage

Having both pango 1.x and pango 2 linked into
the same process will cause trouble, because the
type and function names conflict.

Error out if we detect this situation.

1 files changed, 24 insertions, 0 deletions

diff --git a/pango/pango-context.c b/pango/pango-context.c
index d5e73cfe..a7444865 100644
--- a/pango/pango-context.c
+++ b/pango/pango-context.c
@@ -23,6 +23,8 @@
 #include <string.h>
 #include <stdlib.h>
 
+#include <gio/gio.h>
+
 #include "pango-context.h"
 #include "pango-context-private.h"
 #include "pango-impl-utils.h"
@@ -80,11 +82,33 @@ pango_context_init (PangoContext *context)
   pango_font_description_set_size (context->font_desc, 12 * PANGO_SCALE);
 }
 
+static gboolean
+pango_has_mixed_deps (void)
+{
+  GModule *module;
+  gpointer func;
+  gboolean result = FALSE;
+
+  module = g_module_open (NULL, 0);
+
+  if (g_module_symbol (module, "pango_hb_font_new", &func))
+    result = TRUE;
+
+  g_module_close (module);
+
+  return result;
+}
+
 static void
 pango_context_class_init (PangoContextClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
+ /* Put the check for mixed linkage here, for lack of a better place */
+  if (pango_has_mixed_deps ())
+    g_error ("Pango 2 symbols detected.\n"
+             "Using Pango 1.x and 2 in the same process is not supported.");
+
   object_class->finalize = pango_context_finalize;
 }