3 files changed, 155 insertions, 0 deletions
diff --git a/gdb/infrun.c b/gdb/infrun.c
index e5d2b97..0d7e386 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -4105,6 +4105,44 @@ all_uis_on_sync_execution_starting (void)
     }
 }
 
+/* A quit_handler callback installed while we're handling inferior
+   events.  */
+
+static void
+infrun_quit_handler ()
+{
+  if (target_terminal::is_ours ())
+    {
+      /* Do nothing.
+
+	 default_quit_handler would throw a quit in this case, but if
+	 we're handling an event while we have the terminal, it means
+	 the target is running a background execution command, and
+	 thus when users press Ctrl-C, they're wanting to interrupt
+	 whatever command they were executing in the command line.
+	 E.g.:
+
+	  (gdb) c&
+	  (gdb) foo bar whatever<ctrl-c>
+
+	 That Ctrl-C should clear the input line, not interrupt event
+	 handling if it happens that the user types Ctrl-C at just the
+	 "wrong" time!
+
+	 It's as-if background event handling was handled by a
+	 separate background thread.
+
+	 To be clear, the Ctrl-C is not lost -- it will be processed
+	 by the next QUIT call once we're out of fetch_inferior_event
+	 again.  */
+    }
+  else
+    {
+      if (check_quit_flag ())
+	target_pass_ctrlc ();
+    }
+}
+
 /* Asynchronous version of wait_for_inferior.  It is called by the
    event loop whenever a change of state is detected on the file
    descriptor corresponding to the target.  It can be called more than
@@ -4133,6 +4171,13 @@ fetch_inferior_event ()
   scoped_restore save_pagination
     = make_scoped_restore (&pagination_enabled, false);
 
+  /* Install a quit handler that does nothing if we have the terminal
+     (meaning the target is running a background execution command),
+     so that Ctrl-C never interrupts GDB before the event is fully
+     handled.  */
+  scoped_restore restore_quit_handler
+    = make_scoped_restore (&quit_handler, infrun_quit_handler);
+
   /* End up with readline processing input, if necessary.  */
   {
     SCOPE_EXIT { reinstall_readline_callback_handler_cleanup (); };
diff --git a/gdb/testsuite/gdb.base/bg-exec-sigint-bp-cond.c b/gdb/testsuite/gdb.base/bg-exec-sigint-bp-cond.c
new file mode 100644
index 0000000..b1cf353
--- /dev/null
+++ b/gdb/testsuite/gdb.base/bg-exec-sigint-bp-cond.c
@@ -0,0 +1,33 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2023 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+int
+foo (void)
+{
+  return 0;
+}
+
+int
+main (void)
+{
+  int i;
+
+  for (i = 0; i < 30; i++)
+    foo ();
+
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.base/bg-exec-sigint-bp-cond.exp b/gdb/testsuite/gdb.base/bg-exec-sigint-bp-cond.exp
new file mode 100644
index 0000000..257efb3
--- /dev/null
+++ b/gdb/testsuite/gdb.base/bg-exec-sigint-bp-cond.exp
@@ -0,0 +1,77 @@
+# Copyright 2023 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Check that sending GDB a SIGINT while handling execution control
+# does not interrupt the execution control.
+
+standard_testfile
+
+if {[build_executable "failed to prepare" $testfile $srcfile debug]} {
+    return -1
+}
+
+# Run the test.  Sets a breakpoint with a condition that sends a
+# SIGINT to GDB, and ensures that that doesn't make the breakpoint hit
+# cause a premature stop.  This emulates pressing Ctrl-C just while
+# GDB is evaluating the breakpoint condition.
+proc test {} {
+    clean_restart $::binfile
+
+    if {![runto_main]} {
+	return
+    }
+
+    delete_breakpoints
+
+    set gdb_pid [exp_pid -i [board_info host fileid]]
+
+    # Number of times the breakpoint should be hit before stopping.
+    set num_hits 10
+
+    # A counter used in the breakpoint's condition to ensure that it
+    # causes a stop after NUM_HITS hits.
+    gdb_test "p \$hit_count = 0" " = 0" "reset hit counter"
+
+    # Set a breakpoint with a condition that sends a SIGINT to GDB.  This
+    # emulates pressing Ctrl-C just while GDB is evaluating the breakpoint
+    # condition.
+    gdb_test \
+	"break foo if \$hit_count\+\+ == $num_hits || \$_shell(\"kill -SIGINT $gdb_pid\") != 0" \
+	"Breakpoint .*" \
+	"break foo if <condition>"
+
+    # Number of times we've seen GDB print "Quit" followed by the
+    # prompt.  We should see that exactly $NUM_HITS times.
+    set quit_count 0
+
+    gdb_test_multiple "c&" "SIGINT does not interrupt background execution" {
+	-re "^c&\r\nContinuing\\.\r\n$::gdb_prompt " {
+	    exp_continue
+	}
+	-re "^Quit\r\n$::gdb_prompt " {
+	    incr quit_count
+	    verbose -log "quit_count=$quit_count"
+	    exp_continue
+	}
+	-re "^\r\nBreakpoint .*return 0;" {
+	    gdb_assert {$quit_count == $num_hits} $gdb_test_name
+	}
+	-re ".*Asynchronous execution not supported on this target\..*" {
+	    unsupported "$gdb_test_name (asynchronous execution not supported)"
+	}
+    }
+}
+
+test