[binutils-gdb] Fix regression for multi breakpoints command line clearing.

[Philippe Waroquiers <philippe at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=999700cd99a227bd6848e95cdc99117b2185e84c

commit 999700cd99a227bd6848e95cdc99117b2185e84c
Author: Philippe Waroquiers <philippe.waroquiers@skynet.be>
Date:   Thu Aug 2 23:13:22 2018 +0200

    Fix regression for multi breakpoints command line clearing.
    
    breakpoint.c is modified to fix the regression introduced
    when clearing the commands of several breakpoints by giving an empty
    list of commands, by just typing "end".
    GDB should read an empty list of command once, but it reads
    it for each breakpoint, as an empty list of command is NULL,
    and NULL is interpreted as 'not having read the command list yet'.
    
    The fix consists in having a boolean set to true once the
    command list has been read.
    
    gdb/ChangeLog
    
    2018-08-26  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
    
    	* breakpoint.c (commands_command_1): New boolean cmd_read
    	to detect cmd was already read.

Diff:
---
 gdb/breakpoint.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 8f0feaa..4e7dac5 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -1219,6 +1219,10 @@ commands_command_1 (const char *arg, int from_tty,
 		    struct command_line *control)
 {
   counted_command_line cmd;
+  /* cmd_read will be true once we have read cmd.  Note that cmd might still be
+     NULL after the call to read_command_lines if the user provides an empty
+     list of command by just typing "end".  */
+  bool cmd_read = false;
 
   std::string new_arg;
 
@@ -1235,8 +1239,9 @@ commands_command_1 (const char *arg, int from_tty,
   map_breakpoint_numbers
     (arg, [&] (breakpoint *b)
      {
-       if (cmd == NULL)
+       if (!cmd_read)
 	 {
+	   gdb_assert (cmd == NULL);
 	   if (control != NULL)
 	     cmd = control->body_list_0;
 	   else
@@ -1256,6 +1261,7 @@ commands_command_1 (const char *arg, int from_tty,
 
 	       cmd = read_command_lines (str.c_str (), from_tty, 1, validator);
 	     }
+	   cmd_read = true;
 	 }
 
        /* If a breakpoint was on the list more than once, we don't need to