fix(api): don't override Vimscript SID (#32610)

Problem:  When calling an API from Vimscript to set an option, mapping,
          etc., :verbose shows that it's set from an API client.
Solution: Don't override current_sctx.sc_sid when calling an API from
          Vimscript. Also fix the inverse case where API channel id is
          not set when calling an API from RPC. Move channel id into
          sctx_T to make saving and restoring easier.

Related #8329

2 files changed, 6 insertions, 26 deletions

diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index a1af26e56f..cf82d907a3 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -1049,32 +1049,18 @@ const char *get_default_stl_hl(win_T *wp, bool use_winbar, int stc_hl_id)
   }
 }
 
-int find_sid(uint64_t channel_id)
-{
-  switch (channel_id) {
-  case VIML_INTERNAL_CALL:
-  // TODO(autocmd): Figure out what this should be
-  // return SID_API_CLIENT;
-  case LUA_INTERNAL_CALL:
-    return SID_LUA;
-  default:
-    return SID_API_CLIENT;
-  }
-}
-
 /// Sets sctx for API calls.
 ///
-/// @param channel_id     api clients id. Used to determine if it's a internal
-///                       call or a rpc call.
-/// @return returns       previous value of current_sctx. To be used
-///                       to be used for restoring sctx to previous state.
+/// @param channel_id  api client id to determine if it's a internal or RPC call.
+///
+/// @return  previous value of current_sctx. To be used later for restoring sctx.
 sctx_T api_set_sctx(uint64_t channel_id)
 {
   sctx_T old_current_sctx = current_sctx;
   if (channel_id != VIML_INTERNAL_CALL) {
-    current_sctx.sc_sid =
-      channel_id == LUA_INTERNAL_CALL ? SID_LUA : SID_API_CLIENT;
+    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;
   }
   return old_current_sctx;
 }
diff --git a/src/nvim/api/private/helpers.h b/src/nvim/api/private/helpers.h
index 5cf1ca4d34..d51f99e5ac 100644
--- a/src/nvim/api/private/helpers.h
+++ b/src/nvim/api/private/helpers.h
@@ -186,13 +186,7 @@ typedef struct {
 
 #define WITH_SCRIPT_CONTEXT(channel_id, code) \
   do { \
-    const sctx_T save_current_sctx = current_sctx; \
-    const uint64_t save_channel_id = current_channel_id; \
-    current_sctx.sc_sid = \
-      (channel_id) == LUA_INTERNAL_CALL ? SID_LUA : SID_API_CLIENT; \
-    current_sctx.sc_lnum = 0; \
-    current_channel_id = channel_id; \
+    const sctx_T save_current_sctx = api_set_sctx(channel_id); \
     code; \
-    current_channel_id = save_channel_id; \
     current_sctx = save_current_sctx; \
   } while (0);