REPL: don't record some no-op actions in "undo"

base/repl/LineEdit.jl

@@ -90,9 +90,11 @@ const Region = Pair{<:Integer,<:Integer}
 _region(s) = getmark(s) => position(s)
 region(s) = Pair(extrema(_region(s))...)
 
+bufend(s) = buffer(s).size
+
 indexes(reg::Region) = first(reg)+1:last(reg)
 
-content(s, reg::Region = 0=>buffer(s).size) = String(buffer(s).data[indexes(reg)])
+content(s, reg::Region = 0=>bufend(s)) = String(buffer(s).data[indexes(reg)])
 
 const REGION_ANIMATION_DURATION = Ref(0.2)
 
@@ -769,15 +771,15 @@ function edit_kill_line(s::MIState)
  push_undo(s)
  buf = buffer(s)
  pos = position(buf)
- killbuf = readline(buf, chomp=false)
- if length(killbuf) > 1 && killbuf[end] == '\n'
- killbuf = killbuf[1:end-1]
- char_move_left(buf)
+ endpos = endofline(buf)
+ endpos == pos && buf.size > pos && (endpos += 1)
+ if push_kill!(s, edit_splice!(s, pos => endpos))
+ refresh_line(s)
+ :edit_kill_line
+ else
+ pop_undo(s)
+ :ignore
  end
- push_kill!(s, killbuf) || return :ignore
- edit_splice!(buf, pos => position(buf))
- refresh_line(s)
- :edit_kill_line
 end
 
 function edit_copy_region(s::MIState)
@@ -873,10 +875,13 @@ edit_clear(buf::IOBuffer) = truncate(buf, 0)
 
 function edit_clear(s::MIState)
  push_undo(s)
- push_kill!(s, content(s), false) || return :ignore
- edit_clear(buffer(s))
- refresh_line(s)
- :edit_clear
+ if push_kill!(s, edit_splice!(s, 0 => bufend(s)), false)
+ refresh_line(s)
+ :edit_clear
+ else
+ pop_undo(s)
+ :ignore
+ end
 end
 
 function replace_line(s::PromptState, l::IOBuffer)
@@ -1669,12 +1674,14 @@ function edit_tab(s::MIState, jump_spaces=false, delete_trailing=jump_spaces)
  complete_line(s)
  else
  push_undo(s)
- edit_insert_tab(buffer(s), jump_spaces, delete_trailing)
+ edit_insert_tab(buffer(s), jump_spaces, delete_trailing) || pop_undo(s)
  refresh_line(s)
  :edit_insert_tab
  end
 end
 
+# return true iff the content of the buffer is modified
+# return false when only the position changed
 function edit_insert_tab(buf::IOBuffer, jump_spaces=false, delete_trailing=jump_spaces)
  i = position(buf)
  if jump_spaces && i < buf.size && buf.data[i+1] == _space
@@ -1683,12 +1690,14 @@ function edit_insert_tab(buf::IOBuffer, jump_spaces=false, delete_trailing=jump_
  edit_splice!(buf, i => (spaces == 0 ? buf.size : i+spaces-1))
  else
  jump = spaces == 0 ? buf.size : i+spaces-1
- return seek(buf, jump)
+ seek(buf, jump)
+ return false
  end
  end
  # align to multiples of 4:
  align = 4 - strwidth(String(buf.data[1+beginofline(buf, i):i])) % 4
- return edit_insert(buf, ' '^align)
+ edit_insert(buf, ' '^align)
+ return true
 end
 
 

test/lineedit.jl

@@ -669,6 +669,7 @@ end
  @test edit!(edit_undo!) == "one two three"
 
  @test edit!(LineEdit.edit_clear) == ""
+ @test edit!(LineEdit.edit_clear) == "" # should not be saved twice
  @test edit!(edit_undo!) == "one two three"
 
  @test edit!(LineEdit.edit_insert_newline) == "one two three\n"
@@ -684,6 +685,11 @@ end
  LineEdit.move_line_start(s)
  @test edit!(LineEdit.edit_kill_line) == ""
  @test edit!(edit_undo!) == "one two three"
+ # undo stack not updated if killing nothing:
+ LineEdit.move_line_start(s)
+ LineEdit.edit_kill_line(s)
+ LineEdit.edit_kill_line(s) # no effect
+ @test edit!(edit_undo!) == "one two three"
 
  LineEdit.move_line_start(s)
  LineEdit.edit_kill_line(s)
@@ -747,6 +753,11 @@ end
  @test edit!(LineEdit.edit_tab) == "one two three "
  @test edit!(edit_undo!) == "one two three "
  @test edit!(edit_undo!) == "one two three"
+ LineEdit.move_line_start(s)
+ edit_insert(s, " ")
+ LineEdit.move_line_start(s)
+ @test edit!(s->LineEdit.edit_tab(s, true, true)) == " one two three" # tab moves cursor to position 2
+ @test edit!(edit_undo!) == "one two three" # undo didn't record cursor movement
  # TODO: add tests for complete_line, which don't work directly
 
  # pop initial insert of "one two three"