Piotr Caban : msvcrt: Fix floating point numbers scanning when null-byte is preceding the number.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 287dabd9b6887e94cabfa2a5f9bfe822522095e5
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=287dabd9b6887e94cabfa2a5f9bfe822522095e5

Author: Piotr Caban <piotr at codeweavers.com>
Date:   Mon Jan 13 20:17:17 2020 +0100

msvcrt: Fix floating point numbers scanning when null-byte is preceding the number.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=48452
Signed-off-by: Piotr Caban <piotr at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 dlls/msvcrt/scanf.h       | 2 ++
 dlls/msvcrt/tests/scanf.c | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/dlls/msvcrt/scanf.h b/dlls/msvcrt/scanf.h
index 1833c42dc3..ec3ec79995 100644
--- a/dlls/msvcrt/scanf.h
+++ b/dlls/msvcrt/scanf.h
@@ -393,6 +393,8 @@ _FUNCTION_ {
                     /* skip initial whitespace */
                     while ((nch!=_EOF_) && _ISSPACE_(nch))
                         nch = _GETC_(file);
+                    if (nch == _EOF_)
+                        break;
                     ctx.unget = nch;
 #ifdef STRING
                     ctx.file = file;
diff --git a/dlls/msvcrt/tests/scanf.c b/dlls/msvcrt/tests/scanf.c
index 95fd043e6f..57d9cc0ba1 100644
--- a/dlls/msvcrt/tests/scanf.c
+++ b/dlls/msvcrt/tests/scanf.c
@@ -165,6 +165,12 @@ static void test_sscanf( void )
     ok(double_res >= 1.1e-30-1e-45 && double_res <= 1.1e-30+1e-45,
             "Got %.18le, expected %.18le\n", double_res, 1.1e-30);
 
+    buffer[0] = 0;
+    double_res = 1;
+    ret = p_sscanf(buffer, "%lf", &double_res);
+    ok(ret == -1, "expected 0, got %u\n", ret);
+    ok(double_res == 1, "Got %lf, expected 1\n", double_res);
+
     /* check strings */
     ret = p_sprintf(buffer," %s", pname);
     ok( ret == 26, "expected 26, got %u\n", ret);