fix(lua): don't override script ID from :source (#32626)

Problem:  When setting an option, mapping etc. from Lua without -V1, the
          script ID is set to SID_LUA even if there already is a script
          ID assigned by :source.
Solution: Don't set script ID to SID_LUA if it is already a Lua script.
          Also add _editor.lua to ignorelist to make script context more
          useful when using vim.cmd().

src/nvim/api/private/helpers.c

@@ -30,6 +30,7 @@
 #include "nvim/message.h"
 #include "nvim/msgpack_rpc/unpacker.h"
 #include "nvim/pos_defs.h"
+#include "nvim/runtime.h"
 #include "nvim/types_defs.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
@@ -1057,10 +1058,18 @@ const char *get_default_stl_hl(win_T *wp, bool use_winbar, int stc_hl_id)
 sctx_T api_set_sctx(uint64_t channel_id)
 {
   sctx_T old_current_sctx = current_sctx;
+  // The script context is already properly set when calling an API from Vimscript.
   if (channel_id != VIML_INTERNAL_CALL) {
-    current_sctx.sc_sid = channel_id == LUA_INTERNAL_CALL ? SID_LUA : SID_API_CLIENT;
     current_sctx.sc_lnum = 0;
-    current_sctx.sc_chan = channel_id;
+    if (channel_id == LUA_INTERNAL_CALL) {
+      // When the current script is a Lua script, don't override sc_sid.
+      if (!script_is_lua(current_sctx.sc_sid)) {
+        current_sctx.sc_sid = SID_LUA;
+      }
+    } else {
+      current_sctx.sc_sid = SID_API_CLIENT;
+      current_sctx.sc_chan = channel_id;
+    }
   }
   return old_current_sctx;
 }

src/nvim/eval.c

@@ -7646,22 +7646,8 @@ hashtab_T *find_var_ht_dict(const char *name, const size_t name_len, const char
                  || current_sctx.sc_sid == SID_LUA)
              && current_sctx.sc_sid <= script_items.ga_len) {
     // For anonymous scripts without a script item, create one now so script vars can be used
-    if (current_sctx.sc_sid == SID_LUA) {
-      // try to resolve lua filename & line no so it can be shown in lastset messages.
-      nlua_set_sctx(&current_sctx);
-      if (current_sctx.sc_sid != SID_LUA) {
-        // Great we have valid location. Now here this out we'll create a new
-        // script context with the name and lineno of this one. why ?
-        // for behavioral consistency. With this different anonymous exec from
-        // same file can't access each others script local stuff. We need to do
-        // this all other cases except this will act like that otherwise.
-        bool should_free;
-        // should_free is ignored as script_ctx will be resolved to a fname
-        // and new_script_item() will consume it.
-        char *sc_name = get_scriptname(current_sctx, &should_free);
-        new_script_item(sc_name, &current_sctx.sc_sid);
-      }
-    }
+    // Try to resolve lua filename & linenr so it can be shown in last-set messages.
+    nlua_set_sctx(&current_sctx);
     if (current_sctx.sc_sid == SID_STR || current_sctx.sc_sid == SID_LUA) {
       // Create SID if s: scope is accessed from Lua or anon Vimscript. #15994
       new_script_item(NULL, &current_sctx.sc_sid);

src/nvim/lua/executor.c

@@ -2110,7 +2110,8 @@ bool nlua_execute_on_key(int c, char *typed_buf)
 // @param[out] current
 void nlua_set_sctx(sctx_T *current)
 {
-  if (p_verbose <= 0 || current->sc_sid != SID_LUA) {
+  if (p_verbose <= 0 || (current->sc_sid > 0 && current->sc_lnum > 0)
+      || !script_is_lua(current->sc_sid)) {
     return;
   }
   lua_State *const lstate = global_lstate;
@@ -2119,6 +2120,7 @@ void nlua_set_sctx(sctx_T *current)
   // Files where internal wrappers are defined so we can ignore them
   // like vim.o/opt etc are defined in _options.lua
   char *ignorelist[] = {
+    "vim/_editor.lua",
     "vim/_options.lua",
     "vim/keymap.lua",
   };
@@ -2153,7 +2155,8 @@ void nlua_set_sctx(sctx_T *current)
   if (sid > 0) {
     xfree(source_path);
   } else {
-    new_script_item(source_path, &sid);
+    scriptitem_T *si = new_script_item(source_path, &sid);
+    si->sn_lua = true;
   }
   current->sc_sid = sid;
   current->sc_seq = -1;

src/nvim/runtime.c

@@ -2023,7 +2023,7 @@ static int source_using_linegetter(void *cookie, LineGetter fgetline, const char
   estack_push(ETYPE_SCRIPT, sname, 0);
 
   const sctx_T save_current_sctx = current_sctx;
-  if (current_sctx.sc_sid != SID_LUA) {
+  if (!script_is_lua(current_sctx.sc_sid)) {
     current_sctx.sc_sid = SID_STR;
   }
   current_sctx.sc_seq = 0;
@@ -2241,6 +2241,7 @@ int do_source(char *fname, int check_other, int is_vimrc, int *ret_sid)
   } else {
     // It's new, generate a new SID.
     si = new_script_item(fname_exp, &sid);
+    si->sn_lua = path_with_extension(fname_exp, "lua");
     fname_exp = xstrdup(si->sn_name);  // used for autocmd
     if (ret_sid != NULL) {
       *ret_sid = sid;
@@ -2268,9 +2269,8 @@ int do_source(char *fname, int check_other, int is_vimrc, int *ret_sid)
 
   cookie.conv.vc_type = CONV_NONE;              // no conversion
 
-  if (path_with_extension(fname_exp, "lua")) {
+  if (si->sn_lua) {
     const sctx_T current_sctx_backup = current_sctx;
-    current_sctx.sc_sid = SID_LUA;
     current_sctx.sc_lnum = 0;
     // Source the file as lua
     nlua_exec_file(fname_exp);
@@ -2356,6 +2356,18 @@ theend:
   return retval;
 }
 
+/// Checks if the script with the given script ID is a Lua script.
+bool script_is_lua(scid_T sid)
+{
+  if (sid == SID_LUA) {
+    return true;
+  }
+  if (!SCRIPT_ID_VALID(sid)) {
+    return false;
+  }
+  return SCRIPT_ITEM(sid)->sn_lua;
+}
+
 /// Find an already loaded script "name".
 /// If found returns its script ID.  If not found returns -1.
 int find_script_by_name(char *name)
@@ -2447,7 +2459,8 @@ char *get_scriptname(sctx_T script_ctx, bool *should_free)
   case SID_STR:
     return _("anonymous :source");
   default: {
-    char *const sname = SCRIPT_ITEM(script_ctx.sc_sid)->sn_name;
+    scriptitem_T *const si = SCRIPT_ITEM(script_ctx.sc_sid);
+    char *sname = si->sn_name;
     if (sname == NULL) {
       snprintf(IObuff, IOSIZE, _("anonymous :source (script id %d)"),
                script_ctx.sc_sid);
@@ -2455,7 +2468,13 @@ char *get_scriptname(sctx_T script_ctx, bool *should_free)
     }
 
     *should_free = true;
-    return home_replace_save(NULL, sname);
+    sname = home_replace_save(NULL, sname);
+    if (si->sn_lua && script_ctx.sc_lnum == 0) {
+      char *const ret = concat_str(sname, _(" (run Nvim with -V1 for more details)"));
+      xfree(sname);
+      return ret;
+    }
+    return sname;
   }
   }
 }

src/nvim/runtime_defs.h

@@ -49,6 +49,7 @@ typedef struct {
   scriptvar_T *sn_vars;         ///< stores s: variables for this script
 
   char *sn_name;
+  bool sn_lua;                  ///< true for a lua script
   bool sn_prof_on;              ///< true when script is/was profiled
   bool sn_pr_force;             ///< forceit: profile functions in this script
   proftime_T sn_pr_child;       ///< time set when going into first child