[PATCH] winex11.drv: Fix drawing dashed lines.

[Dmitry Timoshkov]

For some reason XDrawLine() and XDrawRectangle() draw only very first segment
of a dashed line if line_width is set to 0.

I couldn't find an explanation in the XLib programming guide.

In order to see the problem add "X11 Driver"/"ClientSideGraphics"="N" to
the registry, then the bug could be noticed as a missing focus regtangle
on focused buttons, missing dashed lines between nodes in regedit, etc.

Signed-off-by: Dmitry Timoshkov 
---
 dlls/winex11.drv/graphics.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dlls/winex11.drv/graphics.c b/dlls/winex11.drv/graphics.c
index e8c59f9baf..586e64afa1 100644
--- a/dlls/winex11.drv/graphics.c
+++ b/dlls/winex11.drv/graphics.c
@@ -449,6 +449,7 @@ static BOOL X11DRV_SetupGCForPen( X11DRV_PDEVICE *physDev )
     val.line_width = physDev->pen.width;
     if (val.line_width <= 1) {
    val.cap_style = CapNotLast;
+        val.line_width = 1;
     } else {
    switch (physDev->pen.endcap)
    {

[Alexandre Julliard]

Dmitry Timoshkov  writes:
> For some reason XDrawLine() and XDrawRectangle() draw only very first segment
> of a dashed line if line_width is set to 0.
>
> I couldn't find an explanation in the XLib programming guide.
>
> In order to see the problem add "X11 Driver"/"ClientSideGraphics"="N" to
> the registry, then the bug could be noticed as a missing focus regtangle
> on focused buttons, missing dashed lines between nodes in regedit, etc.

That's not the normal X11 behavior, we've been using these dashed lines
for years without issue. It looks like a bug in your graphics driver.

[Dmitry Timoshkov]

Alexandre Julliard  wrote:
> > For some reason XDrawLine() and XDrawRectangle() draw only very first segment
> > of a dashed line if line_width is set to 0.
> >
> > I couldn't find an explanation in the XLib programming guide.
> >
> > In order to see the problem add "X11 Driver"/"ClientSideGraphics"="N" to
> > the registry, then the bug could be noticed as a missing focus regtangle
> > on focused buttons, missing dashed lines between nodes in regedit, etc.
>
> That's not the normal X11 behavior, we've been using these dashed lines
> for years without issue. It looks like a bug in your graphics driver.

Hmm, probably you are right, I don't see this behaviour on another machine
with Linux in a VM.

For the reference this is with xorg-dri-nouveau-17.3.9 and kernel-4.14.52.

Could we add the patch as a workaround? Is there a problem with making sure
that line_width is not 0?

[Alexandre Julliard]

Dmitry Timoshkov  writes:
> Hmm, probably you are right, I don't see this behaviour on another machine
> with Linux in a VM.
>
> For the reference this is with xorg-dri-nouveau-17.3.9 and kernel-4.14.52.
>
> Could we add the patch as a workaround? Is there a problem with making sure
> that line_width is not 0?

It's slower, and at least on my box it causes some glitches in regedit.
Nothing major, but I don't think it's worth changing.