patch 8.2.1426: Vim9: cannot call autoload function in :def function

Problem:    Vim9: cannot call autoload function in :def function.
Solution:   Load the autoload script. (closes #6690)

src/scriptfile.c

@@ -1991,7 +1991,7 @@ autoload_name(char_u *name)
     if (scriptname == NULL)
 	return NULL;
     STRCPY(scriptname, "autoload/");
-    STRCAT(scriptname, name);
+    STRCAT(scriptname, name[0] == 'g' && name[1] == ':' ? name + 2: name);
     for (p = scriptname + 9; (p = vim_strchr(p, AUTOLOAD_CHAR)) != NULL;
 								    q = p, ++p)
 	*p = '/';

src/testdir/test_vim9_expr.vim

@@ -1752,6 +1752,21 @@ def Test_expr7_call()
 	"vim9script",
 	"let x = substitute ('x', 'x', 'x', 'x')"
 	], 'E121:')
+
+  let auto_lines =<< trim END
+      def g:some#func(): string
+	return 'found'
+      enddef
+  END
+  mkdir('Xruntime/autoload', 'p')
+  writefile(auto_lines, 'Xruntime/autoload/some.vim')
+  let save_rtp = &rtp
+  &rtp = getcwd() .. '/Xruntime,' .. &rtp
+  assert_equal('found', g:some#func())
+  assert_equal('found', some#func())
+
+  &rtp = save_rtp
+  delete('Xruntime', 'rf')
 enddef
 
 

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1426,
 /**/
     1425,
 /**/

src/vim9compile.c

@@ -2214,6 +2214,7 @@ compile_call(
     int		error = FCERR_NONE;
     ufunc_T	*ufunc;
     int		res = FAIL;
+    int		is_autoload;
 
     // we can evaluate "has('name')" at compile time
     if (varlen == 3 && STRNCMP(*arg, "has", 3) == 0)
@@ -2258,7 +2259,8 @@ compile_call(
     if (compile_arguments(arg, cctx, &argcount) == FAIL)
 	goto theend;
 
-    if (ASCII_ISLOWER(*name) && name[1] != ':')
+    is_autoload = vim_strchr(name, '#') != NULL;
+    if (ASCII_ISLOWER(*name) && name[1] != ':' && !is_autoload)
     {
 	int	    idx;
 
@@ -2281,8 +2283,9 @@ compile_call(
 
     // If the name is a variable, load it and use PCALL.
     // Not for g:Func(), we don't know if it is a variable or not.
+    // Not for eome#Func(), it will be loaded later.
     p = namebuf;
-    if (STRNCMP(namebuf, "g:", 2) != 0
+    if (STRNCMP(namebuf, "g:", 2) != 0 && !is_autoload
 	    && compile_load(&p, namebuf + varlen, cctx, FALSE) == OK)
     {
 	garray_T    *stack = &cctx->ctx_type_stack;
@@ -2295,7 +2298,7 @@ compile_call(
 
     // A global function may be defined only later.  Need to figure out at
     // runtime.  Also handles a FuncRef at runtime.
-    if (STRNCMP(namebuf, "g:", 2) == 0)
+    if (STRNCMP(namebuf, "g:", 2) == 0 || is_autoload)
 	res = generate_UCALL(cctx, name, argcount);
     else
 	semsg(_(e_unknownfunc), namebuf);

src/vim9execute.c

@@ -545,6 +545,15 @@ call_ufunc(ufunc_T *ufunc, int argcount, ectx_T *ectx, isn_T *iptr)
     return OK;
 }
 
+/*
+ * Return TRUE if an error was given or CTRL-C was pressed.
+ */
+    static int
+vim9_aborting(int prev_called_emsg)
+{
+    return called_emsg > prev_called_emsg || got_int || did_throw;
+}
+
 /*
  * Execute a function by "name".
  * This can be a builtin function or a user function.
@@ -568,6 +577,18 @@ call_by_name(char_u *name, int argcount, ectx_T *ectx, isn_T *iptr)
     }
 
     ufunc = find_func(name, FALSE, NULL);
+
+    if (ufunc == NULL)
+    {
+	int called_emsg_before = called_emsg;
+
+	if (script_autoload(name, TRUE))
+	    // loaded a package, search for the function again
+	    ufunc = find_func(name, FALSE, NULL);
+	if (vim9_aborting(called_emsg_before))
+	    return FAIL;  // bail out if loading the script caused an error
+    }
+
     if (ufunc != NULL)
 	return call_ufunc(ufunc, argcount, ectx, iptr);