Improve coverage of the PR threads/13217 regression test

- Make sure we end up with no thread selected after the detach.

- Test both "thread apply all" and "thread apply $some_threads", for
  completeness.

gdb/ChangeLog:
2017-04-13  Pedro Alves  <palves@redhat.com>

	PR threads/13217
	* gdb.threads/threadapply.exp (thr_apply_detach): New procedure.
	(top level): Call it twice, with different thread sets.

1 files changed, 30 insertions, 1 deletions

diff --git a/gdb/testsuite/gdb.threads/threadapply.exp b/gdb/testsuite/gdb.threads/threadapply.exp
index 789b283..959e8b9 100644
--- a/gdb/testsuite/gdb.threads/threadapply.exp
+++ b/gdb/testsuite/gdb.threads/threadapply.exp
@@ -63,4 +63,33 @@ gdb_test "step" "thread_function.*" "step to the thread_function"
 gdb_test "up" ".*in main.*" "go up in the stack frame" 
 gdb_test "thread apply all print 1"  "Thread ..*\\\$\[0-9]+ = 1.*Thread ..*\\\$\[0-9]+ = 1.*Thread ..*\\\$\[0-9]+ = 1.*Thread ..*\\\$\[0-9]+ = 1.*Thread ..*\\\$\[0-9]+ = 1.*Thread ..*\\\$\[0-9]+ = 1" "run a simple print command on all threads"
 gdb_test "down" "#0.*thread_function.*" "go down and check selected frame"
-gdb_test "thread apply all detach" "Thread .*"
+
+# Make sure that GDB doesn't crash when the previously selected thread
+# exits due to the command run via thread apply.  Regression test for
+# PR threads/13217.
+
+proc thr_apply_detach {thread_set} {
+    with_test_prefix "thread apply $thread_set" {
+	global binfile
+	global break_line
+
+	clean_restart ${binfile}
+
+	if ![runto_main] {
+	    fail "can't run to main"
+	    return -1
+	}
+
+	gdb_breakpoint "$break_line"
+	gdb_continue_to_breakpoint "all threads started"
+
+	gdb_test "thread apply $thread_set detach" "Thread .*"
+	gdb_test "thread" "No thread selected" "switched to no thread selected"
+    }
+}
+
+# Test both "all" and a thread list, because those are implemented as
+# different commands in GDB.
+foreach thread_set {"all" "1.1 1.2 1.3"} {
+    thr_apply_detach $thread_set
+}