[binutils-gdb] Fix latent bug in default_prompt_gdb_start

[binutils-gdb] Fix latent bug in default_prompt_gdb_start

[Tom Tromey]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d394684d5531ea85fc347d68910bed858880f2e0

commit d394684d5531ea85fc347d68910bed858880f2e0
Author: Tom Tromey <tom@tromey.com>
Date:   Wed Jan 11 16:52:38 2023 -0700

    Fix latent bug in default_prompt_gdb_start
    
    default_prompt_gdb_start mimics default_gdb_start, but does not set
    the use_gdb_stub global.  This caused one Python test to work only
    because it used the ordinary gdb_start before later using
    default_prompt_gdb_start.
    
    This patch updates default_prompt_gdb_start to set this global as
    well.

Diff:
---
 gdb/testsuite/lib/prompt.exp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/gdb/testsuite/lib/prompt.exp b/gdb/testsuite/lib/prompt.exp
index a7c34fae2ec..56cafa4dd93 100644
--- a/gdb/testsuite/lib/prompt.exp
+++ b/gdb/testsuite/lib/prompt.exp
@@ -24,6 +24,7 @@
 # uses pass if it sees $gdb_prompt, and fail if it sees $gdb_prompt_fail.
 #
 proc default_prompt_gdb_start { } {
+    global use_gdb_stub
     global GDB
     global INTERNAL_GDBFLAGS GDBFLAGS
     global gdb_prompt
@@ -31,7 +32,17 @@ proc default_prompt_gdb_start { } {
     global timeout
     global gdb_spawn_id
 
+    # Set the default value, it may be overriden later by specific testfile.
+    #
+    # Use `set_board_info use_gdb_stub' for the board file to flag the inferior
+    # is already started after connecting and run/attach are not supported.
+    # This is used for the "remote" protocol.  After GDB starts you should
+    # check global $use_gdb_stub instead of the board as the testfile may force
+    # a specific different target protocol itself.
+    set use_gdb_stub [target_info exists use_gdb_stub]
+
     verbose "Spawning $GDB $INTERNAL_GDBFLAGS $GDBFLAGS"
+    gdb_write_cmd_file "$GDB $INTERNAL_GDBFLAGS $GDBFLAGS"
 
     if [info exists gdb_spawn_id] {
 	return 0