patch 8.2.1392: Vim9: line number incorrect after skipping over comment lines

Problem:    Vim9: error line number incorrect after skipping over comment
            lines.
Solution:   Insert empty lines for skipped lines.
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 649ef48..3cc1e11 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -984,6 +984,47 @@
   echo 'DelMe'
 endfunc
 
+def Test_error_reporting()
+  # comment lines at the start of the function
+  let lines =<< trim END
+    " comment
+    def Func()
+      # comment
+      # comment
+      invalid
+    enddef
+    defcompile
+  END
+  call writefile(lines, 'Xdef')
+  try
+    source Xdef
+  catch /E476:/
+    assert_match('Invalid command: invalid', v:exception)
+    assert_match(', line 3$', v:throwpoint)
+  endtry
+
+  # comment lines after the start of the function
+  lines =<< trim END
+    " comment
+    def Func()
+      let x = 1234
+      # comment
+      # comment
+      invalid
+    enddef
+    defcompile
+  END
+  call writefile(lines, 'Xdef')
+  try
+    source Xdef
+  catch /E476:/
+    assert_match('Invalid command: invalid', v:exception)
+    assert_match(', line 4$', v:throwpoint)
+  endtry
+
+  call delete('Xdef')
+enddef
+
 def Test_deleted_function()
   CheckDefExecFailure([
       'let RefMe: func = function("g:DelMe")',
diff --git a/src/userfunc.c b/src/userfunc.c
index 684a805..10d1c3b 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -2961,6 +2961,18 @@
     // Save the starting line number.
     sourcing_lnum_top = SOURCING_LNUM;
 
+    // Detect having skipped over comment lines to find the return
+    // type.  Add NULL lines to keep the line count correct.
+    sourcing_lnum_off = get_sourced_lnum(eap->getline, eap->cookie);
+    if (SOURCING_LNUM < sourcing_lnum_off)
+    {
+	sourcing_lnum_off -= SOURCING_LNUM;
+	if (ga_grow(&newlines, sourcing_lnum_off) == FAIL)
+	    goto erret;
+	while (sourcing_lnum_off-- > 0)
+	    ((char_u **)(newlines.ga_data))[newlines.ga_len++] = NULL;
+    }
+
     indent = 2;
     nesting = 0;
     nesting_def[nesting] = (eap->cmdidx == CMD_def);
diff --git a/src/version.c b/src/version.c
index 978920e..0f6dfc1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1392,
+/**/
     1391,
 /**/
     1390,