Remeber initial user text for hidden suggestions

When using hidden suggestions remember the text user was typing when
navigating suggestions.

Ensure also that in the previously searched expressiosn we have no
duplicate entries.

data/core/commands/findreplace.lua

@@ -41,6 +41,16 @@ local function update_preview(sel, search_fn, text)
   end
 end
 
+
+local function insert_unique(t, v)
+  local n = #t
+  for i = 1, n do
+    if t[i] == v then return end
+  end
+  t[n + 1] = v
+end
+
+
 local function find(label, search_fn)
   last_view, last_sel, last_finds = core.active_view,
     { core.active_view.doc:get_selection() }, {}
@@ -51,7 +61,7 @@ local function find(label, search_fn)
 
   core.command_view:set_hidden_suggestions()
   core.command_view:enter(label, function(text, item)
-    table.insert(core.previous_find, text)
+    insert_unique(core.previous_find, text)
     core.status_view:remove_tooltip()
     if found then
       last_fn, last_text = search_fn, text
@@ -80,12 +90,13 @@ local function replace(kind, default, fn)
   core.status_view:show_tooltip(get_find_tooltip())
   core.command_view:set_hidden_suggestions()
   core.command_view:enter("Find To Replace " .. kind, function(old)
+    insert_unique(core.previous_find, old)
     core.command_view:set_text(old, true)
 
     local s = string.format("Replace %s %q With", kind, old)
     core.command_view:set_hidden_suggestions()
     core.command_view:enter(s, function(new)
-      table.insert(core.previous_replace, new)
+      insert_unique(core.previous_replace, new)
       local n = doc():replace(function(text)
         return fn(text, old, new)
       end)

data/core/commandview.lua

@@ -89,14 +89,27 @@ end
 
 
 function CommandView:move_suggestion_idx(dir)
-  local current_suggestion = #self.suggestions > 0 and self.suggestions[self.suggestion_idx].text
-  if self.show_suggestions or self:get_text() == current_suggestion then
+  if self.show_suggestions then
     local n = self.suggestion_idx + dir
     self.suggestion_idx = common.clamp(n, 1, #self.suggestions)
-  end
     self:complete()
     self.last_change_id = self.doc:get_change_id()
-  if not self.show_suggestions then
+  else
+    local current_suggestion = #self.suggestions > 0 and self.suggestions[self.suggestion_idx].text
+    local text = self:get_text()
+    if text == current_suggestion then
+      local n = self.suggestion_idx + dir
+      if n == 0 and self.save_suggestion then
+        self:set_text(self.save_suggestion)
+      else
+        self.suggestion_idx = common.clamp(n, 1, #self.suggestions)
+        self:complete()
+      end
+    else
+      self.save_suggestion = text
+      self:complete()
+    end
+    self.last_change_id = self.doc:get_change_id()
     self.state.suggest(self:get_text())
   end
 end
@@ -147,6 +160,7 @@ function CommandView:exit(submitted, inexplicit)
   self.suggestions = {}
   if not submitted then cancel(not inexplicit) end
   self.show_suggestions = true
+  self.save_suggestion = nil
 end