[gdb/testsuite] Add test-case gdb.tui/long-prompt.exp

I noticed that the test-suite doesn't excercise the case in
tui_redisplay_readline that height (initially 1) is changed by this call:
...
    tui_puts_internal (w, prompt, &height);
...

Add a test-case that excercises this.

Tested on x86_64-linux.

diff --git a/gdb/testsuite/gdb.tui/long-prompt.exp b/gdb/testsuite/gdb.tui/long-prompt.exp
new file mode 100644 (file)
index 0000000..e7249bb
--- /dev/null
+++ b/gdb/testsuite/gdb.tui/long-prompt.exp
@@ -0,0 +1,158 @@
+# Copyright 2023 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test a prompt one less than, equal to, and one more than screen width in
+# TUI.
+
+require allow_tui_tests
+
+tuiterm_env
+
+with_test_prefix "prompt size == width + 1" {
+    Term::clean_restart 24 40
+
+    if {![Term::enter_tui]} {
+       unsupported "TUI not supported"
+       return
+    }
+
+    set prompt "123456789A123456789B123456789C123456789D>"
+
+    # Set new prompt, and set old prompt back.
+    send_gdb "set prompt $prompt\n"
+    send_gdb "set prompt (gdb) \n"
+
+    # Expected output:
+    #
+    #   16 (gdb) set prompt 123456789A123456789B123
+    #   17 456789C123456789D>
+    #   18 123456789A123456789B123456789C123456789D
+    #   19 >set prompt (gdb)
+    #   20 (gdb)
+
+    gdb_assert { [Term::wait_for "^>set prompt $gdb_prompt "] } \
+       "got prompt back"
+
+    gdb_assert { $Term::_cur_row == 20 }
+}
+
+with_test_prefix "prompt size == width + 1: end of screen" {
+    Term::clean_restart 24 40
+
+    if {![Term::enter_tui]} {
+       unsupported "TUI not supported"
+       return
+    }
+
+    # Put prompt at last line.
+    Term::command "echo \\n"
+    Term::command "echo \\n"
+    Term::command "echo \\n"
+    Term::command "echo \\n"
+    gdb_assert { $Term::_cur_row == 23 } "at last line"
+
+    set prompt "123456789A123456789B123456789C123456789D>"
+
+    # Set new prompt, and set old prompt back.
+    send_gdb "set prompt $prompt\n"
+    send_gdb "set prompt (gdb) \n"
+
+    # Expected output:
+    #
+    # 19 (gdb) set prompt 123456789A123456789B123
+    # 20 456789C123456789D>
+    # 21 123456789A123456789B123456789C123456789D
+    # 22 >set prompt (gdb)
+    # 23 (gdb)
+
+    gdb_assert { [Term::wait_for "^>set prompt $gdb_prompt "] } \
+       "got prompt back"
+
+    gdb_assert { $Term::_cur_row == 23 } "still at last line"
+    Term::check_region_contents "scrolling" 0 19 40 1 \
+       "^$gdb_prompt set prompt 123456789A123456789B123$"
+}
+
+with_test_prefix "prompt size == width" {
+    Term::clean_restart 24 40
+
+    if {![Term::enter_tui]} {
+       unsupported "TUI not supported"
+       return
+    }
+
+    set prompt "123456789A123456789B123456789C123456789>"
+
+    # Set new prompt, and set old prompt back.
+    send_gdb "set prompt $prompt\n"
+    send_gdb "set prompt (gdb) \n"
+
+    # Expected output:
+    #
+    #   16 (gdb) set prompt 123456789A123456789B123
+    #   17 456789C123456789>
+    #   18 123456789A123456789B123456789C123456789>
+    #   19
+    #   20 123456789A123456789B123456789C123456789>
+    #   21 set prompt (gdb)
+    #   22 (gdb)
+    #
+    # Note that it would be nice to get instead:
+    #
+    #   16 (gdb) set prompt 123456789A123456789B123
+    #   17 456789C123456789>
+    #   18 123456789A123456789B123456789C123456789>
+    #   19 set prompt (gdb)
+    #   20 (gdb)
+    #
+    # The extra newline is added by rl_on_new_line_with_prompt, which decides
+    # this as follows:
+    #  /* If the prompt length is a multiple of real_screenwidth, we don't know
+    #     whether the cursor is at the end of the last line, or already at the
+    #     beginning of the next line. Output a newline just to be safe. */
+
+    gdb_assert { [Term::wait_for "^set prompt $gdb_prompt "] } \
+       "got prompt back"
+
+    gdb_assert { $Term::_cur_row == 22 }
+}
+
+with_test_prefix "prompt size == width - 1" {
+    Term::clean_restart 24 40
+
+    if {![Term::enter_tui]} {
+       unsupported "TUI not supported"
+       return
+    }
+
+    set prompt "123456789A123456789B123456789C12345678>"
+
+    # Set new prompt, and set old prompt back.
+    send_gdb "set prompt $prompt\n"
+    send_gdb "set prompt (gdb) \n"
+
+    # Expected output:
+    #
+    #   16 (gdb) set prompt 123456789A123456789B123
+    #   17 456789C12345678>
+    #   18 123456789A123456789B123456789C12345678>s
+    #   19 et prompt (gdb)
+    #   20 (gdb)
+
+    gdb_assert { [Term::wait_for "^et prompt $gdb_prompt "] } \
+       "got prompt back"
+
+    gdb_assert { $Term::_cur_row == 20 }
+}