From cffdf102d4f01fe5675c389eb80bf55daa62697a Mon Sep 17 00:00:00 2001
From: Gregory Anders <8965202+gpanders@users.noreply.github.com>
Date: Mon, 28 Aug 2023 07:22:19 -0500
Subject: [PATCH] feat(terminal): allow :terminal to take modifiers (#15427)

The following modifiers are all now supported:

    :tab term
    :vertical term
    :horizontal term
    :botright term
    :topleft term

Fixes: https://github.com/neovim/neovim/issues/11385
---
 runtime/doc/news.txt    |  3 +++
 runtime/doc/windows.txt |  3 ++-
 src/nvim/ex_docmd.c     | 30 ++++++++++++++++++++++++------
 3 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 4f9f362b1e..a233b66d1f 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -158,6 +158,9 @@ The following new APIs and features were added.
 • Floating windows can now show footer with new `footer` and `footer_pos`
   config fields. Uses |hl-FloatFooter| by default.
 
+• The |:terminal| command now accepts some |:command-modifiers| (specifically
+  |:horizontal| and those that affect splitting a window).
+
 ==============================================================================
 CHANGED FEATURES                                                 *news-changed*
 
diff --git a/runtime/doc/windows.txt b/runtime/doc/windows.txt
index b78c1eeae5..842542bdc3 100644
--- a/runtime/doc/windows.txt
+++ b/runtime/doc/windows.txt
@@ -243,7 +243,8 @@ and 'winminwidth' are relevant.
 :hor[izontal] {cmd}
 		Execute {cmd}.  Currently only makes a difference for
 		`horizontal wincmd =`, which will equalize windows only
-		horizontally.
+		horizontally, and |:terminal|, which will open a |terminal|
+		buffer in a split window.
 
 :lefta[bove] {cmd}				*:lefta* *:leftabove*
 :abo[veleft] {cmd}				*:abo* *:aboveleft*
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index aba50b2042..3ff1442640 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -7302,12 +7302,31 @@ void set_pressedreturn(bool val)
 static void ex_terminal(exarg_T *eap)
 {
   char ex_cmd[1024];
+  size_t len = 0;
+
+  if (cmdmod.cmod_tab > 0 || cmdmod.cmod_split != 0) {
+    bool multi_mods = false;
+
+    // ex_cmd must be a null terminated string before passing to add_win_cmd_modifiers
+    ex_cmd[0] = '\0';
+
+    len = add_win_cmd_modifiers(ex_cmd, &cmdmod, &multi_mods);
+    assert(len < sizeof(ex_cmd));
+    int result = snprintf(ex_cmd + len, sizeof(ex_cmd) - len, " new");
+    assert(result > 0);
+    len += (size_t)result;
+  } else {
+    int result = snprintf(ex_cmd, sizeof(ex_cmd), "enew%s", eap->forceit ? "!" : "");
+    assert(result > 0);
+    len += (size_t)result;
+  }
+
+  assert(len < sizeof(ex_cmd));
 
   if (*eap->arg != NUL) {  // Run {cmd} in 'shell'.
     char *name = vim_strsave_escaped(eap->arg, "\"\\");
-    snprintf(ex_cmd, sizeof(ex_cmd),
-             ":enew%s | call termopen(\"%s\")",
-             eap->forceit ? "!" : "", name);
+    snprintf(ex_cmd + len, sizeof(ex_cmd) - len,
+             " | call termopen(\"%s\")", name);
     xfree(name);
   } else {  // No {cmd}: run the job with tokenized 'shell'.
     if (*p_sh == NUL) {
@@ -7327,9 +7346,8 @@ static void ex_terminal(exarg_T *eap)
     }
     shell_free_argv(argv);
 
-    snprintf(ex_cmd, sizeof(ex_cmd),
-             ":enew%s | call termopen([%s])",
-             eap->forceit ? "!" : "", shell_argv + 1);
+    snprintf(ex_cmd + len, sizeof(ex_cmd) - len,
+             " | call termopen([%s])", shell_argv + 1);
   }
 
   do_cmdline_cmd(ex_cmd);