From 69082916c8b5d321545d60b9f5facad0a2dd5a4e Mon Sep 17 00:00:00 2001
From: Bram Moolenaar <Bram@vim.org>
Date: Thu, 22 Sep 2022 21:35:19 +0100
Subject: [PATCH] patch 9.0.0552: crash when using NUL in buffer that uses
 :source

Problem:    Crash when using NUL in buffer that uses :source.
Solution:   Don't get a next line when skipping over NL.
---
 src/eval.c                  |  2 +-
 src/testdir/test_source.vim | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/eval.c b/src/eval.c
index 60daca5..8df374a 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -2278,7 +2278,7 @@ eval_next_non_blank(char_u *arg, evalarg_T *evalarg, int *getnext)
 
 	if (next != NULL)
 	{
-	    *getnext = TRUE;
+	    *getnext = *p != NL;
 	    return skipwhite(next);
 	}
     }
diff --git a/src/testdir/test_source.vim b/src/testdir/test_source.vim
index 4736e93..d6aed57 100644
--- a/src/testdir/test_source.vim
+++ b/src/testdir/test_source.vim
@@ -665,5 +665,22 @@ func Test_source_buffer_long_line()
   call delete('Xtest.vim')
 endfunc
 
+func Test_source_buffer_with_NUL_char()
+  " This was trying to use a line below the buffer.
+  let lines =<< trim END
+      if !exists('g:loaded')
+        let g:loaded = 1
+        source
+      endif
+  END
+  " Can't have a NL in heredoc
+  let lines += ["silent! vim9 echo [0 \<NL> ? 'a' : 'b']"]
+  call writefile(lines, 'XsourceNul', '')
+  edit XsourceNul
+  source
+
+  bwipe!
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab
-- 
2.27.0