Re: [RFA] Fix regression in "commands"

[Tom Tromey <tom@tromey.com>]

Pedro> But I'd start with making "commands" not-error like the
Pedro> others.

Ok, how about this?

Tom

commit 657cbb04bd450d2217679d33a91d2342fe02c4b9
Author: Tom Tromey <tom@tromey.com>
Date:   Fri Nov 3 10:26:11 2017 -0600

    Fix regression in "commands"
    
    Pedro pointed out a regression in "commands", where trying to clear a
    breakpoint's command list would fail:
    
        (top-gdb) commands
        Type commands for breakpoint(s) 3, one per line.
        End with a line saying just "end".
        >end
        No breakpoints specified.
        (top-gdb)
    
    I believe the bug was introduced by my patch that changes
    counted_command_line to be a shared_ptr.  This causes the problem
    because now the counted_command_line in commands_command_1 can be NULL,
    whereas previously it never could be.
    
    After some discussion, we agreed to simply remove the error case from
    commands_command_1.
    
    2017-12-07  Tom Tromey  <tom@tromey.com>
    
            PR breakpoints/22511:
            * breakpoint.c (commands_command_1): Don't throw an exception when
            no commands have been read.
    
    2017-12-07  Tom Tromey  <tom@tromey.com>
    
            * gdb.base/break.exp: Add test for empty "commands".

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 54aec7f7d9..7c1dff1c35 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2017-12-07  Tom Tromey  <tom@tromey.com>
+
+	PR breakpoints/22511:
+	* breakpoint.c (commands_command_1): Don't throw an exception when
+	no commands have been read.
+
 2017-12-07  Simon Marchi  <simon.marchi@ericsson.com>
 
 	* common/selftest.h (struct selftest): Add virtual destructor.
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 76bfd53a43..59a4dad3cf 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -1272,9 +1272,6 @@ commands_command_1 (const char *arg, int from_tty,
 	   observer_notify_breakpoint_modified (b);
 	 }
      });
-
-  if (cmd == NULL)
-    error (_("No breakpoints specified."));
 }
 
 static void
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 87547cbe13..d52625bd74 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2017-12-07  Tom Tromey  <tom@tromey.com>
+
+	* gdb.base/break.exp: Add test for empty "commands".
+
 2017-12-07  Phil Muldoon  <pmuldoon@redhat.com>
 
        * gdb.python/py-breakpoint.exp (test_bkpt_explicit_loc): Add new
diff --git a/gdb/testsuite/gdb.base/break.exp b/gdb/testsuite/gdb.base/break.exp
index 96e2f35003..87db2dc0d3 100644
--- a/gdb/testsuite/gdb.base/break.exp
+++ b/gdb/testsuite/gdb.base/break.exp
@@ -854,3 +854,15 @@ gdb_test_no_output "set \$foo=81.5" \
 gdb_test "break $srcfile:\$foo" \
     "Convenience variables used in line specs must have integer values.*" \
     "set breakpoint via non-integer convenience variable disallowed"
+
+
+#
+# Test that commands can be cleared without error.
+#
+
+gdb_test "commands\nprint 232323\nend" ">end" "set some breakpoint commands"
+gdb_test "commands\nend" ">end" "clear breakpoint commands"
+# We verify that the commands were cleared by ensuring that the last
+# breakpoint's location ends the output -- if there were commands,
+# they would have been printed after the location.
+gdb_test "info break" "$srcfile:$line" "verify that they were cleared"