vim-patch:8.2.3889: duplicate code for translating script-local function name

Problem:    Duplicate code for translating script-local function name.
Solution:   Move the code to get_scriptlocal_funcname(). (Yegappan Lakshmanan,
            closes vim/vim#9393)

https://github.com/vim/vim/commit/e7f4abd38b6e05100c699900c8f87281e363beb2

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

5 files changed, 71 insertions, 28 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index c4afd6934c..d8dbcf6eb0 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -5018,18 +5018,11 @@ void common_function(typval_T *argvars, typval_T *rettv, bool is_funcref)
     int arg_idx = 0;
     list_T *list = NULL;
     if (strncmp(s, "s:", 2) == 0 || strncmp(s, "<SID>", 5) == 0) {
-      char sid_buf[25];
-      int off = *s == 's' ? 2 : 5;
-
       // Expand s: and <SID> into <SNR>nr_, so that the function can
       // also be called from another script. Using trans_function_name()
       // would also work, but some plugins depend on the name being
       // printable text.
-      snprintf(sid_buf, sizeof(sid_buf), "<SNR>%" PRId64 "_",
-               (int64_t)current_sctx.sc_sid);
-      name = xmalloc(strlen(sid_buf) + strlen(s + off) + 1);
-      STRCPY(name, sid_buf);
-      STRCAT(name, s + off);
+      name = get_scriptlocal_funcname(s);
     } else {
       name = xstrdup(s);
     }
@@ -5538,6 +5531,14 @@ bool callback_from_typval(Callback *const callback, typval_T *const arg)
       callback->type = kCallbackNone;
       callback->data.funcref = NULL;
     } else {
+      if (arg->v_type == VAR_STRING) {
+        char *newname = get_scriptlocal_funcname(arg->vval.v_string);
+        if (newname != NULL) {
+          xfree(arg->vval.v_string);
+          name = arg->vval.v_string = newname;
+        }
+      }
+
       func_ref((char_u *)name);
       callback->data.funcref = xstrdup(name);
       callback->type = kCallbackFuncref;
diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index 359ce08554..a37613dca9 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -1930,6 +1930,40 @@ theend:
   return (char_u *)name;
 }
 
+/// If the "funcname" starts with "s:" or "<SID>", then expands it to the
+/// current script ID and returns the expanded function name. The caller should
+/// free the returned name. If not called from a script context or the function
+/// name doesn't start with these prefixes, then returns NULL.
+/// This doesn't check whether the script-local function exists or not.
+char *get_scriptlocal_funcname(char *funcname)
+{
+  if (funcname == NULL) {
+    return NULL;
+  }
+
+  if (strncmp(funcname, "s:", 2) != 0
+      && strncmp(funcname, "<SID>", 5) != 0) {
+    // The function name is not a script-local function name
+    return NULL;
+  }
+
+  if (!SCRIPT_ID_VALID(current_sctx.sc_sid)) {
+    emsg(_(e_usingsid));
+    return NULL;
+  }
+
+  char sid_buf[25];
+  // Expand s: and <SID> prefix into <SNR>nr_<name>
+  snprintf(sid_buf, sizeof(sid_buf), "<SNR>%" PRId64 "_",
+           (int64_t)current_sctx.sc_sid);
+  const int off = *funcname == 's' ? 2 : 5;
+  char *newname = xmalloc(strlen(sid_buf) + strlen(funcname + off) + 1);
+  STRCPY(newname, sid_buf);
+  STRCAT(newname, funcname + off);
+
+  return newname;
+}
+
 /// Call trans_function_name(), except that a lambda is returned as-is.
 /// Returns the name in allocated memory.
 char *save_function_name(char **name, bool skip, int flags, funcdict_T *fudi)
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 6d461d9b9d..e67bacce61 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -5170,26 +5170,7 @@ int option_set_callback_func(char *optval, Callback *optcb)
     // treat everything else as a function name string
     tv = xcalloc(1, sizeof(*tv));
     tv->v_type = VAR_STRING;
-
-    // Function name starting with "s:" are supported only in a vimscript
-    // context.
-    if (strncmp(optval, "s:", 2) == 0) {
-      char sid_buf[25];
-
-      if (!SCRIPT_ID_VALID(current_sctx.sc_sid)) {
-        emsg(_(e_usingsid));
-        return FAIL;
-      }
-      // Expand s: prefix into <SNR>nr_<name>
-      snprintf(sid_buf, sizeof(sid_buf), "<SNR>%" PRId64 "_",
-               (int64_t)current_sctx.sc_sid);
-      char *funcname = xmalloc(strlen(sid_buf) + strlen(optval + 2) + 1);
-      STRCPY(funcname, sid_buf);
-      STRCAT(funcname, optval + 2);
-      tv->vval.v_string = funcname;
-    } else {
-      tv->vval.v_string = xstrdup(optval);
-    }
+    tv->vval.v_string = xstrdup(optval);
   }
 
   Callback cb;
diff --git a/src/nvim/testdir/test_expr.vim b/src/nvim/testdir/test_expr.vim
index f33358c59a..47f7f5eb0e 100644
--- a/src/nvim/testdir/test_expr.vim
+++ b/src/nvim/testdir/test_expr.vim
@@ -525,6 +525,21 @@ func Test_funcref()
   call assert_fails('echo function("min") =~ function("min")', 'E694:')
 endfunc
 
+" Test for calling function() and funcref() outside of a Vim script context.
+func Test_function_outside_script()
+  let cleanup =<< trim END
+    call writefile([execute('messages')], 'Xtest.out')
+    qall
+  END
+  call writefile(cleanup, 'Xverify.vim')
+  call RunVim([], [], "-c \"echo function('s:abc')\" -S Xverify.vim")
+  call assert_match('E81: Using <SID> not in a', readfile('Xtest.out')[0])
+  call RunVim([], [], "-c \"echo funcref('s:abc')\" -S Xverify.vim")
+  call assert_match('E81: Using <SID> not in a', readfile('Xtest.out')[0])
+  call delete('Xtest.out')
+  call delete('Xverify.vim')
+endfunc
+
 func Test_setmatches()
   hi def link 1 Comment
   hi def link 2 PreProc
diff --git a/src/nvim/testdir/test_normal.vim b/src/nvim/testdir/test_normal.vim
index d9b392992f..9c5cc51f79 100644
--- a/src/nvim/testdir/test_normal.vim
+++ b/src/nvim/testdir/test_normal.vim
@@ -658,6 +658,18 @@ func Test_opfunc_callback()
   END
   " call CheckScriptSuccess(lines)
 
+  " setting 'opfunc' to a script local function outside of a script context
+  " should fail
+  let cleanup =<< trim END
+    call writefile([execute('messages')], 'Xtest.out')
+    qall
+  END
+  call writefile(cleanup, 'Xverify.vim')
+  call RunVim([], [], "-c \"set opfunc=s:abc\" -S Xverify.vim")
+  call assert_match('E81: Using <SID> not in a', readfile('Xtest.out')[0])
+  call delete('Xtest.out')
+  call delete('Xverify.vim')
+
   " cleanup
   set opfunc&
   delfunc OpFunc1