Rf/autoindentpaste improvements (#30755)

* REPL: disable auto-indent when code is likely being pasted (fix #25186)

On some Windows terminals, pasting is not recognized as such.
This happens also with tmux' builtin paste.
In those cases, auto-indent is better disabled, as we want
to preserve the original indentation of the code being pasted.

This fix is quite a hack, but seems to work: using time(), if
the next character after a newline is being inserted very fast,
assume this was with paste, and cancel the insertion of the
spaces done by auto-indent.

I couldn't insert two characters in a raw within less than
about 0.03 or 0.02 seconds, so the threshold for "very fast"
is set to 0.0005, but this is an option which can changed.

* fix tests

* more reliability

* don't include refresh_line in the timings
* use a separate autoindent variable, as we want to undo indent in case of paste only
  for auto-indented code (although currently in the REPL code this function is never
  called with a positive argument)

* Some improvements: autoident is now prevented and needs not to be redone. Paste of mixed space/tabs/empty lines is now more reliable.

* fixed bug where indent is set externally

Author: oheil

stdlib/REPL/src/LineEdit.jl

@@ -80,6 +80,8 @@ mutable struct PromptState <: ModeState
     refresh_lock::Threads.AbstractLock
     # this would better be Threads.Atomic{Float64}, but not supported on some platforms
     beeping::Float64
+    # this option is to detect when code is pasted in non-"bracketed paste mode" :
+    last_newline::Float64 # register when last newline was entered
 end
 
 options(s::PromptState) =
@@ -685,6 +687,27 @@ edit_splice!(s, ins::AbstractString) = edit_splice!(s, region(s), ins)
 function edit_insert(s::PromptState, c)
     push_undo(s)
     buf = s.input_buffer
+
+    if ! options(s).auto_indent_bracketed_paste
+        pos=position(buf)
+        if pos > 0
+            if buf.data[pos] != _space && string(c) != " "
+                options(s).auto_indent_tmp_off = false
+            end
+            if buf.data[pos] == _space
+                #tabulators are already expanded to space
+                #this expansion may take longer than auto_indent_time_threshold which breaks the timing
+                s.last_newline = time()
+            else
+                #if characters after new line are coming in very fast
+                #its probably copy&paste => switch auto-indent off for the next coming new line
+                if ! options(s).auto_indent_tmp_off && time() - s.last_newline < options(s).auto_indent_time_threshold
+                    options(s).auto_indent_tmp_off = true
+                end
+            end
+        end
+    end
+
     str = string(c)
     edit_insert(buf, str)
     offset = s.ias.curs_row == 1 || s.indent < 0 ?
@@ -715,14 +738,23 @@ end
 function edit_insert_newline(s::PromptState, align::Int = 0 - options(s).auto_indent)
     push_undo(s)
     buf = buffer(s)
-    if align < 0
+    autoindent = align < 0
+    if autoindent && ! options(s).auto_indent_tmp_off
         beg = beginofline(buf)
         align = min(something(findnext(_notspace, buf.data[beg+1:buf.size], 1), 0) - 1,
                     position(buf) - beg) # indentation must not increase
         align < 0 && (align = buf.size-beg)
+    #else
+    #    align = 0
     end
+	align < 0 && (align = 0)
     edit_insert(buf, '\n' * ' '^align)
     refresh_line(s)
+    # updating s.last_newline should happen after refresh_line(s) which can take
+    # an unpredictable amount of time and makes "paste detection" unreliable
+    if ! options(s).auto_indent_bracketed_paste
+        s.last_newline = time()
+    end
 end
 
 # align: delete up to 4 spaces to align to a multiple of 4 chars
@@ -1922,6 +1954,7 @@ function commit_line(s)
 end
 
 function bracketed_paste(s; tabwidth=options(s).tabwidth)
+    options(s).auto_indent_bracketed_paste = true
     ps = state(s, mode(s))
     input = readuntil(ps.terminal, "\e[201~")
     input = replace(input, '\r' => '\n')
@@ -2252,7 +2285,7 @@ run_interface(::Prompt) = nothing
 
 init_state(terminal, prompt::Prompt) =
     PromptState(terminal, prompt, IOBuffer(), :off, IOBuffer[], 1, InputAreaState(1, 1),
-                #=indent(spaces)=# -1, Threads.SpinLock(), 0.0)
+                #=indent(spaces)=# -1, Threads.SpinLock(), 0.0, -Inf)
 
 function init_state(terminal, m::ModalInterface)
     s = MIState(m, m.modes[1], false, IdDict{Any,Any}())

stdlib/REPL/src/REPL.jl

@@ -270,6 +270,10 @@ mutable struct Options
     backspace_adjust::Bool
     confirm_exit::Bool # ^D must be repeated to confirm exit
     auto_indent::Bool # indent a newline like line above
+    auto_indent_tmp_off::Bool # switch auto_indent temporarily off if copy&paste
+    auto_indent_bracketed_paste::Bool # set to true if terminal knows paste mode
+    # cancel auto-indent when next character is entered within this time frame :
+    auto_indent_time_threshold::Float64
 end
 
 Options(;
@@ -283,12 +287,16 @@ Options(;
         beep_use_current = true,
         backspace_align = true, backspace_adjust = backspace_align,
         confirm_exit = false,
-        auto_indent = true) =
+        auto_indent = true,
+        auto_indent_tmp_off = false,
+        auto_indent_bracketed_paste = false,
+        auto_indent_time_threshold = 0.005) =
             Options(hascolor, extra_keymap, tabwidth,
                     kill_ring_max, region_animation_duration,
                     beep_duration, beep_blink, beep_maxduration,
                     beep_colors, beep_use_current,
-                    backspace_align, backspace_adjust, confirm_exit, auto_indent)
+                    backspace_align, backspace_adjust, confirm_exit,
+                    auto_indent, auto_indent_tmp_off, auto_indent_bracketed_paste, auto_indent_time_threshold)
 
 # for use by REPLs not having an options field
 const GlobalOptions = Options()

stdlib/REPL/test/lineedit.jl

@@ -9,7 +9,9 @@ include("FakeTerminals.jl")
 import .FakeTerminals.FakeTerminal
 
 # no need to have animation in tests
-REPL.GlobalOptions.region_animation_duration=0.001
+REPL.GlobalOptions.region_animation_duration=0.0001
+# tests are inserting code much faster than humans
+REPL.GlobalOptions.auto_indent_time_threshold = -0.0
 
 ## helper functions