[Spice-devel] [Win vdagent V2] vdagent: protect against NULL entry in _displays

[Uri Lublin]

rhbz#958051

It may be that a _displays entry will be NULL.
I encountered it when running with multiple QXL devices, for one of
which the driver failed to load since it was "out of resources".

Iterations over _displays should handle that case.
We found four such iterations, and fixed them in this patch.
---

v1->v2: Added missing iteration found by Marc-Andre
        In desktop_layout.cpp -- simplified the added code.

---
 vdagent/desktop_layout.cpp |    7 +++++--
 vdagent/vdagent.cpp        |    9 ++++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/vdagent/desktop_layout.cpp b/vdagent/desktop_layout.cpp
index c474edb..26b6b53 100644
--- a/vdagent/desktop_layout.cpp
+++ b/vdagent/desktop_layout.cpp
@@ -155,7 +155,7 @@ void DesktopLayout::normalize_displays_pos()
 
     for (iter = _displays.begin(); iter != _displays.end(); iter++) {
         mode = *iter;
-        if (mode->_attached) {
+        if (mode && mode->_attached) {
             min_x = min(min_x, mode->_pos_x);
             min_y = min(min_y, mode->_pos_y);
             max_x = max(max_x, mode->_pos_x + (LONG)mode->_width);
@@ -164,7 +164,10 @@ void DesktopLayout::normalize_displays_pos()
     }
     if (min_x || min_y) {
         for (iter = _displays.begin(); iter != _displays.end(); iter++) {
-            (*iter)->move_pos(-min_x, -min_y);
+            mode = *iter;
+            if (mode) {
+                mode->move_pos(-min_x, -min_y);
+            }
         }
     }
     _total_width = max_x - min_x;
diff --git a/vdagent/vdagent.cpp b/vdagent/vdagent.cpp
index 75291b0..a061973 100644
--- a/vdagent/vdagent.cpp
+++ b/vdagent/vdagent.cpp
@@ -618,7 +618,9 @@ bool VDAgent::handle_mon_config(VDAgentMonitorsConfig* mon_config, uint32_t port
     display_count = _desktop_layout->get_display_count();
     for (uint32_t i = 0; i < display_count; i++) {
         DisplayMode* mode = _desktop_layout->get_display(i);
-        ASSERT(mode);
+        if (!mode) {
+            continue;
+        }
         if (i >= mon_config->num_of_monitors) {
             vd_printf("%d. detached", i);
             mode->set_attached(false);
@@ -748,8 +750,9 @@ void VDAgent::set_display_depth(uint32_t depth)
     // setting depth for all the monitors, including unattached ones
     for (uint32_t i = 0; i < display_count; i++) {
         DisplayMode* mode = _desktop_layout->get_display(i);
-        ASSERT(mode);
-        mode->set_depth(depth);
+        if (mode) {
+            mode->set_depth(depth);
+        }
     }
 
     if (display_count) {
-- 
1.7.1