libnm: register empty NMClient and NetworkManager when loading libnm with GIR

Register empty "NMClient" and "NetworkManager" GIR modules as soon as libnm is
loaded witch gnome-introspection. This prevents the real modules from being
loaded because they would in turn load libnm-glib and abort() and crash.

In particular this prevents the GNOME shell from crashing with
libnm-glib abort and allows gracefully disabling the extensions which
use the obsolete library.

Test:

  $ cat test.js
  const NM = imports.gi.NM;
  print (NM.SecretAgentGetSecretsFlags.ALLOW_INTERACTION);

  const NMClient = imports.gi.NMClient;
  print (NMClient.SecretAgentGetSecretsFlags.ALLOW_INTERACTION);

Before:

  $ gjs test.js
  1

  (gjs:16253): libnm-util-ERROR **: libnm symbols detected; Mixing libnm with libnm-util/libnm-glib is not supported
  Trace/breakpoint trap (core dumped)
  $

After:

  $ gjs test.js
  1
  Gjs-Message: JS WARNING: [test.js 5]: reference to undefined property "SecretAgentGetSecretsFlags"

  (gjs:16228): Gjs-WARNING **: JS ERROR: TypeError: NMClient.SecretAgentGetSecretsFlags is undefined
  @test.js:5:1

  JS_EvaluateScript() failed

7 files changed, 145 insertions, 4 deletions

diff --git a/.gitignore b/.gitignore
index cd4fca45a9..c68d11f516 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,7 +6,7 @@
 *.gcno
 *.gcda
 *.la
-*.gir
+*-*.gir
 *.typelib
 **.stamp
 .dirstamp
@@ -177,6 +177,7 @@ test-*.trs
 /libnm-util/tests/test-setting-8021x
 /libnm-util/tests/test-setting-dcb
 
+/libnm/fake-typelib/typelibs.c
 /libnm/nm-settings-ifcfg-rh-docs.xml
 /libnm/nm-property-docs.xml
 /libnm/nm-settings-docs.xml
diff --git a/Makefile.am b/Makefile.am
index cda851a094..58be8ef91c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -858,6 +858,7 @@ nodist_libnminclude_HEADERS += \
 noinst_LTLIBRARIES += libnm/libnm-utils.la
 
 libnm_libnm_utils_la_CPPFLAGS = \
+	$(INTROSPECTION_CFLAGS) \
 	$(libnm_lib_cppflags)
 
 libnm_libnm_utils_la_SOURCES = \
@@ -956,6 +957,23 @@ libnm/libnm.typelib: libnm/libnm.gir
 	$(INTROSPECTION_COMPILER) --includedir=$(srcdir)/libnm-core --includedir=$(builddir)/libnm-core --includedir=$(srcdir)/libnm --includedir=$(builddir)/libnm $< -o $@
 
 INTROSPECTION_GIRS += libnm/NM-1.0.gir
+
+if WITH_FAKE_TYPELIBS
+
+libnm/fake-typelib/NetworkManager.typelib: libnm/fake-typelib/NetworkManager.gir
+	$(AM_V_GEN)  $(INTROSPECTION_COMPILER) $< -o $@
+
+libnm/fake-typelib/NMClient.typelib: libnm/fake-typelib/NMClient.gir
+	$(AM_V_GEN) $(INTROSPECTION_COMPILER) $< -o $@
+
+libnm/fake-typelib/typelibs.c: libnm/fake-typelib/typelibs.gresource.xml libnm/fake-typelib/NetworkManager.typelib libnm/fake-typelib/NMClient.typelib
+	$(AM_V_GEN) $(GLIB_COMPILE_RESOURCES) $< --target=$@ --sourcedir=$(srcdir)/libnm/fake-typelib --generate-source --manual-register --internal
+
+libnm_libnm_utils_la_SOURCES += \
+	libnm/fake-typelib/typelibs.c
+
+endif
+
 endif
 
 if HAVE_INTROSPECTION
diff --git a/configure.ac b/configure.ac
index 061c7738e3..ad188a7763 100644
--- a/configure.ac
+++ b/configure.ac
@@ -322,9 +322,12 @@ GLIB_CFLAGS="$GLIB_CFLAGS -DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_32 -DGLIB_V
 AC_SUBST(GLIB_CFLAGS)
 AC_SUBST(GLIB_LIBS)
 
+GOBJECT_INTROSPECTION_CHECK([0.9.6])
+
 AC_ARG_WITH(libnm-glib,
             AS_HELP_STRING([--without-libnm-glib],
-                           [don't build legacy libraries]))
+                           [don"'"t build legacy libraries]))
+fake_typelibs=no
 if test "$with_libnm_glib" != "no"; then
 	PKG_CHECK_MODULES(DBUS, dbus-1 >= 1.1 dbus-glib-1 >= 0.94, :,
 	                  [AC_MSG_FAILURE([$DBUS_PKG_ERRORS
@@ -333,13 +336,24 @@ Configure with --without-libnm-glib if you do not need the legacy libraries])
 	                  ])
 
 	with_libnm_glib=yes
+
+	if test "${found_introspection}" = "yes"; then
+		AC_PATH_PROG(GLIB_COMPILE_RESOURCES, glib-compile-resources)
+		if ! test x"$GLIB_COMPILE_RESOURCES" = x""; then
+			fake_typelibs=yes
+		fi
+	fi
 fi
 AM_CONDITIONAL(WITH_LEGACY_LIBRARIES, test "$with_libnm_glib" != "no")
+if test "$fake_typelibs" = "yes"; then
+	AC_DEFINE(WITH_FAKE_TYPELIBS, 1, [Define for libnm to prevent GIR from loading libnm-glib])
+else
+	AC_DEFINE(WITH_FAKE_TYPELIBS, 0, [Define for libnm to prevent GIR from loading libnm-glib])
+fi
+AM_CONDITIONAL(WITH_FAKE_TYPELIBS, test "${fake_typelibs}" = "yes")
 
 PKG_CHECK_MODULES([LIBUDEV], [libudev >= 175])
 
-GOBJECT_INTROSPECTION_CHECK([0.9.6])
-
 # Qt4
 PKG_CHECK_MODULES(QT, [QtCore >= 4 QtDBus QtNetwork], [have_qt=yes],[have_qt=no])
 AC_ARG_ENABLE(qt,
diff --git a/libnm/fake-typelib/NMClient.gir b/libnm/fake-typelib/NMClient.gir
new file mode 100644
index 0000000000..3002f8d630
--- /dev/null
+++ b/libnm/fake-typelib/NMClient.gir
@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+<!-- A lame duck typelib which prevents GIR from loading the
+     real one (which would crash due to conflict with libnm) -->
+<repository version="1.2"
+            xmlns="http://www.gtk.org/introspection/core/1.0"
+            xmlns:c="http://www.gtk.org/introspection/c/1.0"
+            xmlns:glib="http://www.gtk.org/introspection/glib/1.0">
+	<namespace name="NMClient" version="0.0" />
+</repository>
diff --git a/libnm/fake-typelib/NetworkManager.gir b/libnm/fake-typelib/NetworkManager.gir
new file mode 100644
index 0000000000..d15d29afc7
--- /dev/null
+++ b/libnm/fake-typelib/NetworkManager.gir
@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<!-- A lame duck typelib which prevents GIR from loading the
+     real one (which would crash due to conflict with libnm) -->
+<repository version="1.2"
+            xmlns="http://www.gtk.org/introspection/core/1.0"
+            xmlns:c="http://www.gtk.org/introspection/c/1.0"
+            xmlns:glib="http://www.gtk.org/introspection/glib/1.0">
+	<namespace name="NetworkManager" version="0.0">
+	</namespace>
+</repository>
diff --git a/libnm/fake-typelib/typelibs.gresource.xml b/libnm/fake-typelib/typelibs.gresource.xml
new file mode 100644
index 0000000000..9a71d97544
--- /dev/null
+++ b/libnm/fake-typelib/typelibs.gresource.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<gresources>
+	<gresource prefix="/org/freedesktop/libnm/fake-typelib">
+		<file>NetworkManager.typelib</file>
+		<file>NMClient.typelib</file>
+	</gresource>
+</gresources>
diff --git a/libnm/nm-libnm-utils.c b/libnm/nm-libnm-utils.c
index fbbfe2c552..a01228d5bb 100644
--- a/libnm/nm-libnm-utils.c
+++ b/libnm/nm-libnm-utils.c
@@ -23,6 +23,8 @@
 
 #include "nm-libnm-utils.h"
 
+#include <girepository.h>
+
 /*****************************************************************************/
 
 char *
@@ -160,3 +162,83 @@ next:
 	nm_assert (g_utf8_validate (desc_full, -1, NULL));
 	return desc_full;
 }
+
+#if WITH_FAKE_TYPELIBS
+
+/*
+ * Here we register empty "NMClient" and "NetworkManager" GIR modules as soon
+ * as we are loaded (if gnome-introspection is being used). This prevents the
+ * real modules from being loaded because they would in turn load libnm-glib
+ * and abort() and crash.
+ *
+ * For the high level languages that utilize GIR the crash is highly inconvenient
+ * while the inability to resolve any methods and attributes is potentially
+ * recoverable.
+ */
+
+GResource *typelibs_get_resource (void);
+void typelibs_register_resource (void);
+
+static void __attribute__((constructor))
+_nm_libnm_utils_init (void)
+{
+	GITypelib *typelib;
+	GBytes *data;
+	const char *namespace;
+	GModule *self;
+	GITypelib *(*_g_typelib_new_from_const_memory) (const guint8 *memory,
+	                                                gsize len,
+	                                                GError **error) = NULL;
+	const char *(*_g_irepository_load_typelib) (GIRepository *repository,
+	                                            GITypelib *typelib,
+	                                            GIRepositoryLoadFlags flags,
+	                                            GError **error) = NULL;
+	const char *names[] = { "/org/freedesktop/libnm/fake-typelib/NetworkManager.typelib",
+	                        "/org/freedesktop/libnm/fake-typelib/NMClient.typelib" };
+	int i;
+
+	self = g_module_open (NULL, 0);
+	if (!self)
+		return;
+	g_module_symbol (self, "g_typelib_new_from_const_memory",
+	                 (gpointer *) &_g_typelib_new_from_const_memory);
+	if (_g_typelib_new_from_const_memory) {
+		g_module_symbol (self, "g_irepository_load_typelib",
+		                 (gpointer *) &_g_irepository_load_typelib);
+	}
+	g_module_close (self);
+
+	if (!_g_typelib_new_from_const_memory || !_g_irepository_load_typelib)
+		return;
+
+	typelibs_register_resource ();
+
+	for (i = 0; i < 2; i++) {
+		gs_free_error GError *error = NULL;
+
+		data = g_resource_lookup_data (typelibs_get_resource (),
+		                               names[i],
+		                               G_RESOURCE_LOOKUP_FLAGS_NONE,
+		                               &error);
+		if (!data) {
+			g_warning ("Fake typelib %s could not be loaded: %s", names[i], error->message);
+			return;
+		}
+
+		typelib = _g_typelib_new_from_const_memory (g_bytes_get_data (data, NULL),
+		                                            g_bytes_get_size (data),
+		                                            &error);
+		if (!typelib) {
+			g_warning ("Could not create fake typelib instance %s: %s", names[i], error->message);
+			return;
+		}
+
+		namespace = _g_irepository_load_typelib (NULL, typelib, 0, &error);
+		if (!namespace) {
+			g_warning ("Could not load fake typelib %s: %s", names[i], error->message);
+			return;
+		}
+	}
+}
+
+#endif /* WITH_FAKE_TYPELIBS */