PR guile/17203

	* guile/scm-param.c (pascm_parameter_defined_p): New function.
	(gdbscm_register_parameter_x): Call it.  Raise error for pre-existing
	parameters.

	testsuite/
	* gdb.guile/scm-parameter.exp: Add tests for trying to create
	previously existing parameter, and previously ambiguously spelled
	parameter.
Fix PR 17206

As reported in PR 17206, an internal error is triggered when command
until is executed.  In infcmd.c:until_next_command, step_range_end is
set to 'pc',

  if (!func)
    {
      struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (pc);

      if (msymbol.minsym == NULL)
	error (_("Execution is not within a known function."));

      tp->control.step_range_start = BMSYMBOL_VALUE_ADDRESS (msymbol);
      tp->control.step_range_end = pc;
    }

and later in infrun.c:resume, the assert below is triggered in PR
17206.

  if (tp->control.may_range_step)
    {
      /* If we're resuming a thread with the PC out of the step
	 range, then we're doing some nested/finer run control
	 operation, like stepping the thread out of the dynamic
	 linker or the displaced stepping scratch pad.  We
	 shouldn't have allowed a range step then.  */
      gdb_assert (pc_in_thread_step_range (pc, tp));
    }

In until_next_command, we set step range to [XXX, pc), so pc isn't
within the range.  pc_in_thread_step_range returns false and the
assert is triggered.  AFAICS, the range we want in until_next_command
is [XXX, pc] instead of [XXX, pc), because we want to program step
until greater than pc.  This patch is to set step_range_end to
'pc + 1'.  Running until-nodebug.exp with unpatched GDB will get the
following fail,

FAIL: gdb.base/until-nodebug.exp: until 2 (GDB internal error)

and the fail goes away when the fix is applied.

gdb:

2014-07-29  Yao Qi  <yao@codesourcery.com>

	PR gdb/17206
	* infcmd.c (until_next_command): Set step_range_end to PC + 1.

gdb/testsuite:

2014-07-29  Yao Qi  <yao@codesourcery.com>

	PR gdb/17206
	* gdb.base/until-nodebug.exp: New.
Update gdb/NEWS in preparation for GDB 7.8 release.

gdb/ChangeLog:

	* NEWS: Change "Changes since GDB 7.7" into "Changes in GDB 7.8".
Set GDB version number to 7.8.

gdb/ChangeLog:

	* version.in: Set GDB version number to 7.8.
Document the GDB 7.8 release in gdb/ChangeLog

gdb/ChangeLog:

	GDB 7.8 released.
Bump GDB version number to 7.8.0.DATE-cvs.

gdb/ChangeLog:

	* version.in: Set GDB version number to 7.8.0.DATE-cvs.
Automatic date update in version.in