[RTEMS Project] #4096: shell: CRTL-U sets the cursor to the wrong position

[RTEMS trac]

#4096: shell: CRTL-U sets the cursor to the wrong position
----------------------+-----------------------------
  Reporter:  frank_k  |      Owner:  Sebastian Huber
      Type:  defect   |     Status:  assigned
  Priority:  normal   |  Milestone:  5.2
 Component:  shell    |    Version:
  Severity:  normal   |   Keywords:
Blocked By:           |   Blocking:
----------------------+-----------------------------
 This patch fixes a tiny bug in the command line editing of the RTEMS
 shell.
 Typing CTRL-U in the shell should remove all characters left of the
 cursor.
 After pressing CTRL-U, the current implementation does wrongly place the
 cursor
 at the end of the line instead at its beginning.

 To reproduce the bug, start the shell and type 'abc123' (no <RETURN>):

 {{{
 ~/src/rtems $ qemu-system-arm -net none -nographic -M realview-pbx-a9 -m
 256M -kernel build/arm/realview_pbx_a9_qemu/testsuites/libtests/dl10.exe
 *** BEGIN OF TEST libdl (RTL) 10 ***
 *** TEST VERSION: 6.0.0.d9bdf166644f612dd628fe4951c12c6f8e94ba5f
 *** TEST STATE: USER_INPUT
 *** TEST BUILD: RTEMS_DEBUG RTEMS_NETWORKING RTEMS_POSIX_API RTEMS_SMP
 *** TEST TOOLS: 10.2.1 20200904 \
 (RTEMS 6, RSB 31f936a7b74d60bda609a9960c6e1a705ba54974, Newlib a0d7982)
 RTL (libdl) commands: dl, rtl


 RTEMS Shell on /dev/foobar. Use 'help' to list commands.
 SHLL [/] # abc123
 }}}

 Then move the cursor onto the '1' by hitting three times the <ARROW-LEFT>
 key.
 Next type <CTRL>-U:

 {{{
 SHLL [/] # 123
 }}}

 Note that the cursor is at the end of the line (after '3') instead of
 correctly
 at the beginning (on the '1'), now.

 Continuing typing 'echo ' incorrectly results in the output:

 {{{
 SHLL [/] # 123echo 123
 }}}

 The patch changes this behavior so that the cursor in the second last step
 will
 be on the '1' and typing 'echo ' will then correctly reflected as:

 {{{
 SHLL [/] # echo 123
 }}}

--
Ticket URL: <http://devel.rtems.org/ticket/4096>
RTEMS Project <http://www.rtems.org/>
RTEMS Project