Do not consider prompt line as changed when push-enabled

This leads to a flicker on command prompt where the idle callback
decides to redraw even though nothing changed (and it used to wrongly
redraw the empty prompt as error, which is now fixed).

As a consequence of this change, incremental search does not apply
automatically to initial empty searches anymmore, which may be a bit
better to avoid the window jumping around.

Fixes #5405

Author: mawww

src/input_handler.cc

@@ -1089,8 +1089,6 @@ class Prompt : public InputMode
                     context().client().menu_select(0);
             }
         }
-        else
-            m_line_changed = true;
 
         if (not (context().flags() & Context::Flags::Draft))
             m_idle_timer.set_next_date(Clock::now() + get_idle_timeout(context()));

src/normal.cc

@@ -535,7 +535,7 @@ void command(const Context& context, EnvVarMap env_vars, char reg = 0)
                 if (event == PromptEvent::Change)
                 {
                     auto info = CommandManager::instance().command_info(context, cmdline);
-                    context.input_handler().set_prompt_face(context.faces()[info ? "Prompt" : "Error"]);
+                    context.input_handler().set_prompt_face(context.faces()[info or cmdline.empty() ? "Prompt" : "Error"]);
 
                     auto autoinfo = context.options()["autoinfo"].get<AutoInfo>();
                     if (autoinfo & AutoInfo::Command)

test/regression/5405-error-face-on-empty-prompt/cmd

@@ -0,0 +1 @@
+

test/regression/5405-error-face-on-empty-prompt/in

@@ -0,0 +1 @@
+

test/regression/5405-error-face-on-empty-prompt/script

@@ -0,0 +1,9 @@
+ui_out -until '{ "jsonrpc": "2.0", "method": "refresh", "params": [true] }'
+ui_in '{ "jsonrpc": "2.0", "method": "keys", "params": [ ":" ] }'
+ui_out '{ "jsonrpc": "2.0", "method": "draw_status", "params": [[{ "face": { "fg": "yellow", "bg": "default", "underline": "default", "attributes": [] }, "contents": ":" }, { "face": { "fg": "blue", "bg": "default", "underline": "default", "attributes": [] }, "contents": "" }, { "face": { "fg": "black", "bg": "cyan", "underline": "default", "attributes": [] }, "contents": " " }], [{ "face": { "fg": "default", "bg": "default", "underline": "default", "attributes": [] }, "contents": "out 1:1 " }, { "face": { "fg": "black", "bg": "yellow", "underline": "default", "attributes": [] }, "contents": "" }, { "face": { "fg": "default", "bg": "default", "underline": "default", "attributes": [] }, "contents": " " }, { "face": { "fg": "yellow", "bg": "default", "underline": "default", "attributes": [] }, "contents": "prompt" }, { "face": { "fg": "default", "bg": "default", "underline": "default", "attributes": [] }, "contents": " - client0@[kak-tests]" }], { "fg": "cyan", "bg": "default", "underline": "default", "attributes": [] }] }'
+ui_in '{ "jsonrpc": "2.0", "method": "keys", "params": [ "a<backspace>" ] }'
+ui_out -ignore 2
+ui_out '{ "jsonrpc": "2.0", "method": "draw_status", "params": [[{ "face": { "fg": "yellow", "bg": "default", "underline": "default", "attributes": [] }, "contents": ":" }, { "face": { "fg": "blue", "bg": "default", "underline": "default", "attributes": [] }, "contents": "" }, { "face": { "fg": "black", "bg": "cyan", "underline": "default", "attributes": [] }, "contents": " " }], [{ "face": { "fg": "default", "bg": "default", "underline": "default", "attributes": [] }, "contents": "out 1:1 " }, { "face": { "fg": "black", "bg": "yellow", "underline": "default", "attributes": [] }, "contents": "" }, { "face": { "fg": "default", "bg": "default", "underline": "default", "attributes": [] }, "contents": " " }, { "face": { "fg": "yellow", "bg": "default", "underline": "default", "attributes": [] }, "contents": "prompt" }, { "face": { "fg": "default", "bg": "default", "underline": "default", "attributes": [] }, "contents": " - client0@[kak-tests]" }], { "fg": "cyan", "bg": "default", "underline": "default", "attributes": [] }] }'
+ui_out -ignore 3
+# Error face redraw was happening here
+ui_out '{ "jsonrpc": "2.0", "method": "set_cursor", "params": ["prompt", { "line": 0, "column": 1 }] }'