[Spice-devel] [linux/vd-agent v1 6/7] x11-randr: simplest fix for address-of-packed-member

[Victor Toso]

From: Victor Toso <me at victortoso.com>

The struct type for width/height is uint32_t while we are trying to
access and change it with int* - code can be improved a bit in following
patches but this one fixes the warning by copying the value from the
struct and copying back new value afterwards.

Also:
- Moved variables to internal scope;
- Added braces to inner if;

 > src/vdagent/x11-randr.c: In function ‘zero_base_monitors’:
 >     src/vdagent/x11-randr.c:621:28: error: taking address of packed member of
 >     ‘struct VDAgentMonConfig’ may result in an unaligned pointer value
 > [-Werror=address-of-packed-member]
 >   621 |         mon_width = (int *)&mon_config->monitors[i].width;
 >       |                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 > src/vdagent/x11-randr.c:622:29: error: taking address of packed member of
 >     ‘struct VDAgentMonConfig’ may result in an unaligned pointer value
 >     [-Werror=address-of-packed-member]
 >   622 |         mon_height = (int *)&mon_config->monitors[i].height;
 >       |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Victor Toso <victortoso at redhat.com>
---
 src/vdagent/x11-randr.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/vdagent/x11-randr.c b/src/vdagent/x11-randr.c
index 924f5ec..7585031 100644
--- a/src/vdagent/x11-randr.c
+++ b/src/vdagent/x11-randr.c
@@ -611,20 +611,24 @@ static void zero_base_monitors(struct vdagent_x11 *x11,
                                int *width, int *height)
 {
     int i, min_x = INT_MAX, min_y = INT_MAX, max_x = INT_MIN, max_y = INT_MIN;
-    int *mon_height, *mon_width;
 
     for (i = 0; i < mon_config->num_of_monitors; i++) {
-        if (!monitor_enabled(&mon_config->monitors[i]))
+        int mon_height, mon_width;
+
+        if (!monitor_enabled(&mon_config->monitors[i])) {
             continue;
+        }
         mon_config->monitors[i].x &= ~7;
         mon_config->monitors[i].width &= ~7;
-        mon_width = (int *)&mon_config->monitors[i].width;
-        mon_height = (int *)&mon_config->monitors[i].height;
-        constrain_to_screen(x11, mon_width, mon_height);
+        mon_width = mon_config->monitors[i].width;
+        mon_height = mon_config->monitors[i].height;
+        constrain_to_screen(x11, &mon_width, &mon_height);
         min_x = MIN(mon_config->monitors[i].x, min_x);
         min_y = MIN(mon_config->monitors[i].y, min_y);
-        max_x = MAX(mon_config->monitors[i].x + *mon_width, max_x);
-        max_y = MAX(mon_config->monitors[i].y + *mon_height, max_y);
+        max_x = MAX(mon_config->monitors[i].x + mon_width, max_x);
+        max_y = MAX(mon_config->monitors[i].y + mon_height, max_y);
+        mon_config->monitors[i].width = mon_width;
+        mon_config->monitors[i].height = mon_height;
     }
     if (min_x != 0 || min_y != 0) {
         syslog(LOG_ERR, "%s: agent config %d,%d rooted, adjusting to 0,0.",
-- 
2.21.0