vim-patch:9.0.1734: :runtime completion fails for multiple args (#24767)

Problem: :runtime completion fails for multiple args
Solution: Make it work

closes: vim/vim#12616

https://github.com/vim/vim/commit/be5cdd1d634c2dfc7e415499fb18f4d246a8721c

2 files changed, 11 insertions, 2 deletions

diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index c6efb4b3b4..4030d818c8 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -1376,7 +1376,7 @@ char *skiptowhite(const char *p)
 /// @param p
 ///
 /// @return Pointer to the next whitespace character.
-char *skiptowhite_esc(char *p)
+char *skiptowhite_esc(const char *p)
   FUNC_ATTR_PURE
 {
   while (*p != ' ' && *p != '\t' && *p != NUL) {
@@ -1385,7 +1385,7 @@ char *skiptowhite_esc(char *p)
     }
     p++;
   }
-  return p;
+  return (char *)p;
 }
 
 /// Skip over text until '\n' or NUL.
diff --git a/src/nvim/runtime.c b/src/nvim/runtime.c
index 290b773371..89ffecd333 100644
--- a/src/nvim/runtime.c
+++ b/src/nvim/runtime.c
@@ -265,6 +265,15 @@ void set_context_in_runtime_cmd(expand_T *xp, const char *arg)
   char *p = skiptowhite(arg);
   runtime_expand_flags
     = *p != NUL ? get_runtime_cmd_flags((char **)&arg, (size_t)(p - arg)) : 0;
+  // Skip to the last argument.
+  while (*(p = skiptowhite_esc(arg)) != NUL) {
+    if (runtime_expand_flags == 0) {
+      // When there are multiple arguments and [where] is not specified,
+      // use an unrelated non-zero flag to avoid expanding [where].
+      runtime_expand_flags = DIP_ALL;
+    }
+    arg = skipwhite(p);
+  }
   xp->xp_context = EXPAND_RUNTIME;
   xp->xp_pattern = (char *)arg;
 }