commit f5d639a8af719eb8ecb141b5c0890627e4d83134
author Dominique Pelle <dominique.pelle@gmail.com> Wed Jan 12 15:24:40 2022 +0000
committer Bram Moolenaar <Bram@vim.org> Wed Jan 12 15:24:40 2022 +0000
tree 2890e8ac277b77edd6cb76464a54ff30af478d3f
parent 5d9826973d9f4c6ffbb5648676bb628660c62906

patch 8.2.4070: using uninitialized memory when reading empty file

Problem:    Using uninitialized memory when reading empty file.
Solution:   Check for empty file before checking for NL. (Dominique Pellé,
            closes #9511)

src/filepath.c

diff --git a/src/filepath.c b/src/filepath.c
index eb5b8e0..add74b4 100644
--- a/src/filepath.c
+++ b/src/filepath.c
@@ -1796,7 +1796,7 @@
 		p < buf + readlen || (readlen <= 0 && (prevlen > 0 || binary));
 		++p)
 	{
-	    if (*p == '\n' || readlen <= 0)
+	    if (readlen <= 0 || *p == '\n')
 	    {
 		listitem_T  *li;
 		char_u	    *s	= NULL;

src/testdir/test_eval_stuff.vim

diff --git a/src/testdir/test_eval_stuff.vim b/src/testdir/test_eval_stuff.vim
index ac9589d..ff6d695 100644
--- a/src/testdir/test_eval_stuff.vim
+++ b/src/testdir/test_eval_stuff.vim
@@ -93,6 +93,13 @@
   call delete('XReadfile_bin')
 endfunc
 
+func Test_readfile_binary_empty()
+  call writefile([], 'Xempty-file')
+  " This used to compare uninitialized memory in Vim <= 8.2.4065
+  call assert_equal([''], readfile('Xempty-file', 'b'))
+  call delete('Xempty-file')
+endfunc
+
 func Test_readfile_bom()
   call writefile(["\ufeffFOO", "FOO\ufeffBAR"], 'XReadfile_bom')
   call assert_equal(['FOO', 'FOOBAR'], readfile('XReadfile_bom'))

src/version.c

diff --git a/src/version.c b/src/version.c
index a931516..8c77e2e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4070,
+/**/
     4069,
 /**/
     4068,