Remove redraw coalescing logic

Prior to this change, if we saw more than one repaint readline command in
a row, we would try to ignore the second one. However this was never the
right thing to do since sometimes we really do need to repaint twice in a
row (e.g. the user hits Ctrl+L twice). Previously we were saved by the
buginess of this mechanism but with the repainting refactoring we see
missing redraws.

Remove the coalescing logic and add a test. Fixes #7280.

build_tools/pexpect_helper.py

@@ -197,10 +197,10 @@ class SpawnedProc(object):
         """ Cover over expect_re() which accepts a literal string. """
         return self.expect_re(re.escape(s), **kwargs)
 
-    def expect_prompt(self, *args, **kwargs):
+    def expect_prompt(self, increment=True, *args, **kwargs):
         """ Convenience function which matches some text and then a prompt.
             Match the given positional arguments as expect_re, and then look
-            for a prompt, bumping the prompt counter.
+            for a prompt, bumping the prompt counter if increment is true.
             Returns None on success, and exits on failure.
             Example:
                sp.sendline("echo hello world")
@@ -212,7 +212,8 @@ class SpawnedProc(object):
             get_prompt_re(self.prompt_counter),
             pat_desc="prompt %d" % self.prompt_counter,
         )
-        self.prompt_counter += 1
+        if increment:
+            self.prompt_counter += 1
 
     def report_exception_and_exit(self, pat, unmatched, err):
         """ Things have gone badly.

src/reader.cpp

@@ -2645,9 +2645,6 @@ struct readline_loop_state_t {
 
     /// Maximum number of characters to read.
     size_t nchars{std::numeric_limits<size_t>::max()};
-
-    /// \return whether the last readline command was a repaint.
-    bool last_was_repaint() const { return last_cmd && *last_cmd == readline_cmd_t::repaint; }
 };
 
 /// Read normal characters, inserting them into the command line.
@@ -2767,12 +2764,10 @@ void reader_data_t::handle_readline_command(readline_cmd_t c, readline_loop_stat
         }
         case rl::force_repaint:
         case rl::repaint: {
-            if (force_exec_prompt_and_repaint || !rls.last_was_repaint()) {
-                exec_prompt();
-                s_reset_line(&screen, true /* redraw prompt */);
-                this->layout_and_repaint(L"readline");
-                force_exec_prompt_and_repaint = false;
-            }
+            exec_prompt();
+            s_reset_line(&screen, true /* redraw prompt */);
+            this->layout_and_repaint(L"readline");
+            force_exec_prompt_and_repaint = false;
             break;
         }
         case rl::complete:

tests/pexpects/bind.py

@@ -3,7 +3,13 @@ from pexpect_helper import SpawnedProc
 
 sp = SpawnedProc()
 send, sendline, sleep, expect_prompt = sp.send, sp.sendline, sp.sleep, sp.expect_prompt
-expect_prompt()
+expect_prompt(increment=False)
+
+# Clear twice (regression test for #7280).
+send("\f")
+expect_prompt(increment=False)
+send("\f")
+expect_prompt(increment=False)
 
 # Fish should start in default-mode (i.e., emacs) bindings. The default escape
 # timeout is 30ms.