[PATCH v2 0/2] MR5854: win32u: get_char_dimensions set height to 1 when failed

[Fan WenJie (＠fanwenjie)]

Signed-off-by: Fan WenJie

when get_char_dimensions failed, width not set, width may be undefined value and cause undefined behaviour

--
  v2: win32u: memset 0 to metric in get_text_metr_size

https://gitlab.winehq.org/wine/wine/-/merge_requests/5854

[PATCH v2 1/2] win32u: get_char_dimensions set height to 1 when failed

[Fan WenJie]

From: Fan WenJie

Signed-off-by: Fan WenJie 
---
 dlls/win32u/sysparams.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/dlls/win32u/sysparams.c b/dlls/win32u/sysparams.c
index 71e52b71719..e0fb536f7b0 100644
--- a/dlls/win32u/sysparams.c
+++ b/dlls/win32u/sysparams.c
@@ -4323,13 +4323,16 @@ LONG get_char_dimensions( HDC hdc, TEXTMETRICW *metric, int *height )
          'r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H',
          'I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};

-    if (metric && !NtGdiGetTextMetricsW( hdc, metric, 0 )) return 0;
+    if (metric && !NtGdiGetTextMetricsW( hdc, metric, 0 )) goto fail;

if (!NtGdiGetTextExtentExW( hdc, abcdW, ARRAYSIZE(abcdW), 0, NULL, NULL, &sz, 0 ))
-        return 0;
+        goto fail;

if (height) *height = sz.cy;
     return (sz.cx / 26 + 1) / 2;
+fail:
+    if (height) *height = 1;
+    return 0;
 }

/* get text metrics and/or "average" char width of the specified logfont

[PATCH v2 2/2] win32u: memset 0 to metric in get_text_metr_size

[Fan WenJie]

From: Fan WenJie

Signed-off-by: Fan WenJie 
---
 dlls/win32u/sysparams.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dlls/win32u/sysparams.c b/dlls/win32u/sysparams.c
index e0fb536f7b0..cf5859e490b 100644
--- a/dlls/win32u/sysparams.c
+++ b/dlls/win32u/sysparams.c
@@ -4343,6 +4343,7 @@ static void get_text_metr_size( HDC hdc, LOGFONTW *lf, TEXTMETRICW *metric, UINT
     TEXTMETRICW tm;
     UINT ret;
     if (!metric) metric = &tm;
+    memset(metric, 0, sizeof(*metric));
     hfont = NtGdiHfontCreate( lf, sizeof(*lf), 0, 0, NULL );
     if (!hfont || !(hfontsav = NtGdiSelectFont( hdc, hfont )))
     {