Indicate batch mode failures by exiting with nonzero status

This commit causes GDB in batch mode to exit with nonzero status
if the last command to be executed fails.

gdb/ChangeLog:

	PR gdb/13000:
	* gdb/main.c (captured_main_1): Exit with nonzero status
	in batch mode if the last command to be executed failed.
	* NEWS: Mention the above.

gdb/testsuite/ChangeLog:

	PR gdb/13000:
	* gdb.base/batch-exit-status.exp: New file.
	* gdb.base/batch-exit-status.good-commands: Likewise.
	* gdb.base/batch-exit-status.bad-commands: Likewise.

1 files changed, 3 insertions, 0 deletions

diff --git a/gdb/NEWS b/gdb/NEWS
index 45514b1..0ad8ae5 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -10,6 +10,9 @@
 * DWARF index cache: GDB can now automatically save indices of DWARF
   symbols on disk to speed up further loading of the same binaries.
 
+* GDB in batch mode now exits with status 1 if the last command to be
+  executed failed.
+
 * New commands
 
 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND