patch 8.1.0161: buffer not updated with 'autoread' set if file was deleted

Problem:    Buffer not updated with 'autoread' set if file was deleted.
            (Michael Naumann)
Solution:   Don't set the timestamp to zero. (closes #3165)

src/fileio.c

@@ -6923,11 +6923,13 @@ buf_check_timestamp(
     {
 	retval = 1;
 
-	/* set b_mtime to stop further warnings (e.g., when executing
-	 * FileChangedShell autocmd) */
+	// set b_mtime to stop further warnings (e.g., when executing
+	// FileChangedShell autocmd)
 	if (stat_res < 0)
 	{
-	    buf->b_mtime = 0;
+	    // When 'autoread' is set we'll check the file again to see if it
+	    // re-appears.
+	    buf->b_mtime = buf->b_p_ar;
 	    buf->b_orig_size = 0;
 	    buf->b_orig_mode = 0;
 	}

src/testdir/test_stat.vim

@@ -46,6 +46,15 @@ func Test_existent_directory()
   call assert_equal('rwx', getfperm(dname)[0:2])
 endfunc
 
+func SleepForTimestamp()
+  " FAT has a granularity of 2 seconds, otherwise it's usually 1 second
+  if has('win32')
+    sleep 2
+  else
+    sleep 1
+  endif
+endfunc
+
 func Test_checktime()
   let fname = 'Xtest.tmp'
 
@@ -53,12 +62,7 @@ func Test_checktime()
   call writefile(fl, fname)
   set autoread
   exec 'e' fname
-  " FAT has a granularity of 2 seconds, otherwise it's usually 1 second
-  if has('win32')
-    sleep 2
-  else
-    sleep 1
-  endif
+  call SleepForTimestamp()
   let fl = readfile(fname)
   let fl[0] .= ' - checktime'
   call writefile(fl, fname)
@@ -68,6 +72,46 @@ func Test_checktime()
   call delete(fname)
 endfunc
 
+func Test_autoread_file_deleted()
+  new Xautoread
+  set autoread
+  call setline(1, 'original')
+  w!
+
+  call SleepForTimestamp()
+  if has('win32')
+    silent !echo changed > Xautoread
+  else
+    silent !echo 'changed' > Xautoread
+  endif
+  checktime
+  call assert_equal('changed', trim(getline(1)))
+
+  call SleepForTimestamp()
+  messages clear
+  if has('win32')
+    silent !del Xautoread
+  else
+    silent !rm Xautoread
+  endif
+  checktime
+  call assert_match('E211:', execute('messages'))
+  call assert_equal('changed', trim(getline(1)))
+
+  call SleepForTimestamp()
+  if has('win32')
+    silent !echo recreated > Xautoread
+  else
+    silent !echo 'recreated' > Xautoread
+  endif
+  checktime
+  call assert_equal('recreated', trim(getline(1)))
+
+  call delete('Xautoread')
+  bwipe!
+endfunc
+
+
 func Test_nonexistent_file()
   let fname = 'Xtest.tmp'
 

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    161,
 /**/
     160,
 /**/