patch 9.1.1892: Not possible to know once Vim is done with sourcing vimrc

Problem:   A plugin does not know when startup scripts were already
           triggered. This is useful to determine if a function is
           called inside vimrc or after (like when sourcing 'plugin/'
           files).
Solution:  Add the v:vim_did_init variable (Evgeni Chasnovski)

closes: #18668

Signed-off-by: Evgeni Chasnovski <evgeni.chasnovski@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 9.1.  Last change: 2025 Oct 26
+*eval.txt*	For Vim version 9.1.  Last change: 2025 Nov 01
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -2988,6 +2988,10 @@ v:versionlong	Like v:version, but also including the patchlevel in the last
 v:vim_did_enter	Zero until most of startup is done.  It is set to one just
 		before |VimEnter| autocommands are triggered.
 
+				*v:vim_did_init* *vim_did_init-variable*
+v:vim_did_init	Zero until initialization is done.  It is set to one just
+		after |vimrc| is sourced and before |load-plugins|.
+
 					*v:warningmsg* *warningmsg-variable*
 v:warningmsg	Last given warning message.  It's allowed to set this
 		variable.

runtime/doc/repeat.txt

@@ -1,4 +1,4 @@
-*repeat.txt*    For Vim version 9.1.  Last change: 2025 Oct 13
+*repeat.txt*    For Vim version 9.1.  Last change: 2025 Nov 01
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -328,6 +328,12 @@ For writing a Vim script, see chapter 41 of the user manual |usr_41.txt|.
 			you will need to write `filetype plugin indent on`
 			AFTER all `packadd!` commands.
 
+			To programmatically decide if `!` is needed during
+			startup, check |v:vim_did_init|: use `!` if 0 (to not
+			duplicate |load-plugins| step), no `!` otherwise (to
+			force load plugin files as otherwise they won't be
+			loaded automatically).
+
 			Also see |pack-add|.
 			{only available when compiled with |+eval|}
 

runtime/doc/starting.txt

@@ -1,4 +1,4 @@
-*starting.txt*  For Vim version 9.1.  Last change: 2025 Oct 12
+*starting.txt*  For Vim version 9.1.  Last change: 2025 Nov 01
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -843,6 +843,9 @@ accordingly.  Vim proceeds in this order:
 	If Vim was started in Ex mode with the "-s" argument, all following
 	initializations until 4. are skipped.  Only the "-u" option is
 	interpreted.
+
+	The |v:vim_did_init| variable is set to 1 after this step is finished.
+
 							*evim.vim*
      a. If Vim was started as |evim| or |eview| or with the |-y| argument, the
 	script $VIMRUNTIME/evim.vim will be loaded.

runtime/doc/tags

@@ -11360,6 +11360,7 @@ v:var	eval.txt	/*v:var*
 v:version	eval.txt	/*v:version*
 v:versionlong	eval.txt	/*v:versionlong*
 v:vim_did_enter	eval.txt	/*v:vim_did_enter*
+v:vim_did_init	eval.txt	/*v:vim_did_init*
 v:warningmsg	eval.txt	/*v:warningmsg*
 v:wayland_display	eval.txt	/*v:wayland_display*
 v:windowid	eval.txt	/*v:windowid*
@@ -11634,6 +11635,7 @@ vim:	options.txt	/*vim:*
 vim_announce	intro.txt	/*vim_announce*
 vim_dev	intro.txt	/*vim_dev*
 vim_did_enter-variable	eval.txt	/*vim_did_enter-variable*
+vim_did_init-variable	eval.txt	/*vim_did_init-variable*
 vim_mac	intro.txt	/*vim_mac*
 vim_starting	builtin.txt	/*vim_starting*
 vim_use	intro.txt	/*vim_use*

runtime/doc/version9.txt

@@ -1,4 +1,4 @@
-*version9.txt*  For Vim version 9.1.  Last change: 2025 Oct 26
+*version9.txt*  For Vim version 9.1.  Last change: 2025 Nov 01
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -41908,6 +41908,7 @@ Vim Variables: ~
 |v:termda1|		The escape sequence returned for the primary device
 			attribute query (DA1).
 |v:termosc|		The most recent received OSC response.
+|v:vim_did_init|	Set once Vim finishes startup initialization.
 |v:wayland_display|	The name of the Wayland display Vim is connected to.
 
 Vim Arguments: ~

runtime/syntax/vim.vim

@@ -2,7 +2,7 @@
 " Language:	   Vim script
 " Maintainer:	   Hirohito Higashi <h.east.727 ATMARK gmail.com>
 "	   Doug Kearns <dougkearns@gmail.com>
-" Last Change:	   2025 Oct 27
+" Last Change:	   2025 Nov 01
 " Former Maintainer: Charles E. Campbell
 
 " DO NOT CHANGE DIRECTLY.
@@ -166,7 +166,7 @@ syn keyword vimFuncName contained win_execute win_findbuf win_getid win_gettype
 " Predefined variable names {{{2
 " GEN_SYN_VIM: vimVarName, START_STR='syn keyword vimVimVarName contained', END_STR=''
 syn keyword vimVimVarName contained count count1 prevcount errmsg warningmsg statusmsg shell_error this_session version lnum termresponse fname lang lc_time ctype charconvert_from charconvert_to fname_in fname_out fname_new fname_diff cmdarg foldstart foldend folddashes foldlevel progname servername dying exception throwpoint register cmdbang insertmode val key profiling fcs_reason fcs_choice beval_bufnr beval_winnr beval_winid beval_lnum beval_col beval_text scrollstart swapname swapchoice swapcommand char mouse_win mouse_winid mouse_lnum mouse_col operator searchforward hlsearch oldfiles windowid progpath completed_item option_new option_old option_oldlocal option_oldglobal option_command option_type errors false true none null numbermax numbermin numbersize
-syn keyword vimVimVarName contained vim_did_enter testing t_number t_string t_func t_list t_dict t_float t_bool t_none t_job t_channel t_blob t_class t_object termrfgresp termrbgresp termu7resp termstyleresp termblinkresp event versionlong echospace argv collate exiting colornames sizeofint sizeoflong sizeofpointer maxcol python3_version t_typealias t_enum t_enumvalue stacktrace t_tuple wayland_display clipmethod termda1 termosc
+syn keyword vimVimVarName contained vim_did_enter testing t_number t_string t_func t_list t_dict t_float t_bool t_none t_job t_channel t_blob t_class t_object termrfgresp termrbgresp termu7resp termstyleresp termblinkresp event versionlong echospace argv collate exiting colornames sizeofint sizeoflong sizeofpointer maxcol python3_version t_typealias t_enum t_enumvalue stacktrace t_tuple wayland_display clipmethod termda1 termosc vim_did_init
 
 "--- syntax here and above generated by runtime/syntax/generator/gen_syntax_vim.vim ---
 

src/evalvars.c

@@ -167,6 +167,7 @@ static struct vimvar
     {VV_NAME("clipmethod",	 VAR_STRING), NULL, VV_RO},
     {VV_NAME("termda1",		 VAR_STRING), NULL, VV_RO},
     {VV_NAME("termosc",	 VAR_STRING), NULL, VV_RO},
+    {VV_NAME("vim_did_init",	 VAR_NUMBER), NULL, VV_RO},
 };
 
 // shorthand

src/main.c

@@ -433,6 +433,10 @@ main
     // Source startup scripts.
     source_startup_scripts(&params);
 
+#ifdef FEAT_EVAL
+    set_vim_var_nr(VV_VIM_DID_INIT, 1L);
+#endif
+
 #ifdef FEAT_MZSCHEME
     /*
      * Newer version of MzScheme (Racket) require earlier (trampolined)

src/testdir/test_startup.vim

@@ -71,6 +71,36 @@ func Test_after_comes_later()
   call delete('Xsequence')
 endfunc
 
+func Test_vim_did_init()
+  let before =<< trim [CODE]
+    set nocp viminfo+=nviminfo
+    set guioptions+=M
+    set loadplugins
+    set rtp=Xhere
+    set nomore
+  [CODE]
+
+  let after =<< trim [CODE]
+    redir! > Xtestout
+    echo g:var_vimrc
+    echo g:var_plugin
+    redir END
+    quit
+  [CODE]
+
+  call writefile(['let g:var_vimrc=v:vim_did_init'], 'Xvimrc', 'D')
+  call mkdir('Xhere/plugin', 'pR')
+  call writefile(['let g:var_plugin=v:vim_did_init'], 'Xhere/plugin/here.vim')
+
+  if RunVim(before, after, '-u Xvimrc')
+    let lines = readfile('Xtestout')
+    call assert_equal('0', lines[1])
+    call assert_equal('1', lines[2])
+  endif
+
+  call delete('Xtestout')
+endfunc
+
 func Test_pack_in_rtp_when_plugins_run()
   CheckFeature packages
   let before =<< trim [CODE]

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1892,
 /**/
     1891,
 /**/

src/vim.h

@@ -2256,7 +2256,8 @@ typedef int sock_T;
 #define VV_CLIPMETHOD 113
 #define VV_TERMDA1 114
 #define VV_TERMOSC 115
-#define VV_LEN		116	// number of v: vars
+#define VV_VIM_DID_INIT		116
+#define VV_LEN		117	// number of v: vars
 
 // used for v_number in VAR_BOOL and VAR_SPECIAL
 #define VVAL_FALSE	0L	// VAR_BOOL