V6 GFX: Fix bugs in graphics compatibility with V5 applications

svn path=/trunk/boinc/; revision=13830

checkin_notes

@@ -9426,3 +9426,13 @@ Charlie 10 Oct 2007
     mac_build/
         boinc.xcodeproj/
             project.pbxproj
+
+Charlie 11 Oct 2007
+    - V6 GFX: Fix bugs in graphics compatibility with V5 applications:
+        - Initialize APP_VERSION::graphics_exec_path to empty string.
+        - Remember previous graphics mode when setting V5 applications 
+            to MODE_FULLSCREEN and restore mode when exiting fullscreen.
+    client/
+        app.h
+        app_graphics.C
+        client_state.C

client/app.h

@@ -116,6 +116,7 @@ public:
     // info related to app's graphics mode (win, screensaver, etc.)
     //
     int graphics_mode_acked;            // mode acked by app
+    int graphics_mode_before_ss;        // mode before last screensaver request
     double graphics_mode_ack_timeout;
     bool exit_requested;
     int premature_exit_count;

client/app_graphics.C

@@ -46,6 +46,18 @@ void ACTIVE_TASK::request_graphics_mode(GRAPHICS_MSG& m) {
 
     if (!app_client_shm.shm) return;
 
+    if (m.mode == MODE_FULLSCREEN) {
+        // Remember mode before screensaver
+        graphics_mode_before_ss = graphics_mode_acked;
+    } else if (graphics_mode_acked != MODE_FULLSCREEN) {
+        graphics_mode_before_ss = MODE_HIDE_GRAPHICS;
+    }
+
+    if ( (m.mode == MODE_HIDE_GRAPHICS) && (graphics_mode_acked == MODE_FULLSCREEN) ) {
+        // Restore mode from before screensaver
+        m.mode = graphics_mode_before_ss;
+    }
+    
     graphics_msg = m;       // save graphics_station, desktop, display
 
     strcpy(buf, xml_graphics_modes[m.mode]);

client/client_state.C

@@ -731,6 +731,8 @@ int CLIENT_STATE::link_app_version(PROJECT* p, APP_VERSION* avp) {
         );
         return ERR_NOT_UNIQUE;
     }
+    
+    avp->graphics_exec_path[0] = 0;
 
     for (i=0; i<avp->app_files.size(); i++) {
         FILE_REF& file_ref = avp->app_files[i];