From: Tom Tromey <tom@tromey.com>
Date: Tue, 16 Jun 2020 23:48:38 +0000 (-0600)
Subject: Fix crash when TUI window creation fails
X-Git-Url: http://git.efficios.com/?a=commitdiff_plain;ds=sidebyside;h=d2d1ea20aef6ed97232280b5e15a52b8d7dc7b7d;p=deliverable%2Fbinutils-gdb.git

Fix crash when TUI window creation fails

If a TUI window is written in Python, and if the window construction
function fails, then gdb will crash.  This patch fixes the crash.

gdb/ChangeLog
2020-06-16  Tom Tromey  <tom@tromey.com>

	* python/py-tui.c (tui_py_window::~tui_py_window): Handle case
	where m_window==nullptr.

gdb/testsuite/ChangeLog
2020-06-16  Tom Tromey  <tom@tromey.com>

	* gdb.python/tui-window.py (failwin): New function.  Register it
	as a TUI window type.
	* gdb.python/tui-window.exp: Create new "fail" layout.  Test it.
---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 08362f291d..cb3761c1ba 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-06-16  Tom Tromey  <tom@tromey.com>
+
+	* python/py-tui.c (tui_py_window::~tui_py_window): Handle case
+	where m_window==nullptr.
+
 2020-06-15  Tom Tromey  <tromey@adacore.com>
 
 	* windows-nat.c (windows_nat::handle_output_debug_string):
diff --git a/gdb/python/py-tui.c b/gdb/python/py-tui.c
index ca88f85eb9..95c71f1d2d 100644
--- a/gdb/python/py-tui.c
+++ b/gdb/python/py-tui.c
@@ -133,7 +133,10 @@ tui_py_window::~tui_py_window ()
 {
   gdbpy_enter enter_py (get_current_arch (), current_language);
 
-  if (PyObject_HasAttrString (m_window.get (), "close"))
+  /* This can be null if the user-provided Python construction
+     function failed.  */
+  if (m_window != nullptr
+      && PyObject_HasAttrString (m_window.get (), "close"))
     {
       gdbpy_ref<> result (PyObject_CallMethod (m_window.get (), "close",
 					       nullptr));
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index d2ed9db4eb..97fecf6791 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2020-06-16  Tom Tromey  <tom@tromey.com>
+
+	* gdb.python/tui-window.py (failwin): New function.  Register it
+	as a TUI window type.
+	* gdb.python/tui-window.exp: Create new "fail" layout.  Test it.
+
 2020-06-16  Gary Benson <gbenson@redhat.com>
 
 	* gdb.python/py-nested-maps.c (create_map): Add missing return
diff --git a/gdb/testsuite/gdb.python/tui-window.exp b/gdb/testsuite/gdb.python/tui-window.exp
index 503823a229..f0fdd96e1a 100644
--- a/gdb/testsuite/gdb.python/tui-window.exp
+++ b/gdb/testsuite/gdb.python/tui-window.exp
@@ -36,6 +36,7 @@ gdb_test_no_output "source ${remote_python_file}" \
     "source ${testfile}.py"
 
 gdb_test_no_output "tui new-layout test test 1 status 0 cmd 1"
+gdb_test_no_output "tui new-layout fail fail 1 status 0 cmd 1"
 
 if {![Term::enter_tui]} {
     unsupported "TUI not supported"
@@ -49,3 +50,5 @@ Term::check_contents "Window display" "Test: 0"
 Term::resize 51 51
 # Remember that a resize request actually does two resizes...
 Term::check_contents "Window was updated" "Test: 2"
+
+Term::command "layout fail"
diff --git a/gdb/testsuite/gdb.python/tui-window.py b/gdb/testsuite/gdb.python/tui-window.py
index 4deb585f13..f362b8768a 100644
--- a/gdb/testsuite/gdb.python/tui-window.py
+++ b/gdb/testsuite/gdb.python/tui-window.py
@@ -35,3 +35,9 @@ class TestWindow:
         self.count = self.count + 1
 
 gdb.register_window_type("test", TestWindow)
+
+# A TUI window "constructor" that always fails.
+def failwin(win):
+    raise RuntimeError("Whoops")
+
+gdb.register_window_type("fail", failwin)