# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1639660502 -3600
# Node ID 22896e358a906d8c9f07eacf543f870e4a1bdb31
# Parent  c929ca14d8a9f29e4a0b2f34a236adcf87fd55a5
patch 8.2.3824: no ASAN support for MSVC

Commit: https://github.com/vim/vim/commit/6df0f2759d12ec0bc999b2963ecea4387a2bc516
Author: Yegappan Lakshmanan <yegappan@yahoo.com>
Date:   Thu Dec 16 13:06:10 2021 +0000

    patch 8.2.3824: no ASAN support for MSVC

    Problem:    No ASAN support for MSVC.
    Solution:   Add ASAN support and fix a coupld of uncovered problems. (Yegappan
                Lakshmanan, closes #9357)

diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -147,6 +147,8 @@
 #
 #	Static Code Analysis: ANALYZE=yes (works with VS2012 or later)
 #
+#	Address Sanitizer: ASAN=yes (works with VS2019 or later)
+#
 # You can combine any of these interfaces
 #
 # Example: To build the non-debug, GUI version with Perl interface:
@@ -662,6 +664,12 @@ CFLAGS = $(CFLAGS) -DHAVE_STDINT_H
 CFLAGS = $(CFLAGS) /analyze
 !endif
 
+# Address Sanitizer (ASAN) generally available starting with VS2019 version
+# 16.9
+!if ("$(ASAN)" == "yes") && ($(MSVC_MAJOR) >= 14)
+CFLAGS = $(CFLAGS) /fsanitize=address
+!endif
+
 !ifdef NODEBUG
 VIM = vim
 ! if "$(OPTIMIZE)" == "SPACE"
diff --git a/src/findfile.c b/src/findfile.c
--- a/src/findfile.c
+++ b/src/findfile.c
@@ -2653,7 +2653,7 @@ simplify_filename(char_u *filename)
 
     p = filename;
 # ifdef BACKSLASH_IN_FILENAME
-    if (p[1] == ':')	    // skip "x:"
+    if (p[0] != NUL && p[1] == ':')	    // skip "x:"
 	p += 2;
 # endif
 
diff --git a/src/os_mswin.c b/src/os_mswin.c
--- a/src/os_mswin.c
+++ b/src/os_mswin.c
@@ -389,6 +389,8 @@ mch_isFullName(char_u *fname)
     // Another way to check is to use mch_FullName() and see if the result is
     // the same as the name or mch_FullName() fails.  However, this has quite a
     // bit of overhead, so let's not do that.
+    if (*fname == NUL)
+	return TRUE;
     return ((ASCII_ISALPHA(fname[0]) && fname[1] == ':'
 				      && (fname[2] == '/' || fname[2] == '\\'))
 	    || (fname[0] == fname[1] && (fname[0] == '/' || fname[0] == '\\')));
diff --git a/src/testdir/test_fnamemodify.vim b/src/testdir/test_fnamemodify.vim
--- a/src/testdir/test_fnamemodify.vim
+++ b/src/testdir/test_fnamemodify.vim
@@ -93,6 +93,7 @@ func Test_fnamemodify_er()
   call assert_equal('b.c', fnamemodify('a.b.c.d.e', ':r:r:e:e:e'))
   call assert_equal('b.c', fnamemodify('a.b.c.d.e', ':r:r:e:e:e:e'))
 
+  call assert_equal('', fnamemodify('', ':p:t'))
   call assert_equal('', fnamemodify(test_null_string(), test_null_string()))
 endfunc
 
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3824,
+/**/
     3823,
 /**/
     3822,