PR threads/2015: Fix adjust_pc_after_break for thread debugging

[Andreas Schwab <schwab@suse.de>]

adjust_pc_after_break is doing the wrong thing during thread debugging
when the current thread is different from the thread when the debuggee was
stopped last.  The problem is that it calls currently_stepping, which
accesses global variables that are part of the thread context.  But the
context switch will only happen much later on.  The proposed fix will skip
the call when the current infrun context does not match the thread to be
examined.  This has been tested on x86_64-suse-linux and fixes 32
testcases without any regressions.

Andreas.

2005-09-28  Andreas Schwab  <schwab@suse.de>

	PR threads/2015
	* infrun.c (adjust_pc_after_break): Don't use the state from a
	non-matching thread context.

--- gdb/infrun.c	01 Aug 2005 11:52:13 +0200	1.203
+++ gdb/infrun.c	28 Sep 2005 00:03:47 +0200	
@@ -1200,8 +1200,12 @@ adjust_pc_after_break (struct execution_
       /* When using hardware single-step, a SIGTRAP is reported for
          both a completed single-step and a software breakpoint.  Need
          to differentiate between the two as the latter needs
-         adjusting but the former does not.  */
-      if (currently_stepping (ecs))
+         adjusting but the former does not.
+
+         When the thread to be examined does not match the current thread
+         context we can't use currently_stepping, so assume no
+         single-stepping in this case.  */
+      if (ptid_equal (ecs->ptid, inferior_ptid) && currently_stepping (ecs))
 	{
 	  if (prev_pc == breakpoint_pc
 	      && software_breakpoint_inserted_here_p (breakpoint_pc))

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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