Avoid regenerating the land tabs over top of themselves

This was only occurring when hooks caused a GUI reload, which is
somewhat unsafe, but this seems like a useful precaution to take.

src/equipment.c

@@ -234,6 +234,9 @@ void equipment_open( unsigned int wid )
    GLfloat colour[4*4];
    const char *buf;
 
+   /* Mark as generated. */
+   land_tabGenerate(LAND_WINDOW_EQUIPMENT);
+
    /* Set global WID. */
    equipment_wid = wid;
 

src/land.c

@@ -69,6 +69,8 @@
 #define has_visited(f)        (land_visited & (f)) /**< Check if player has visited. */
 static unsigned int land_visited = 0; /**< Contains what the player visited. */
 
+/* Which tabs have been generated by their respective open functions. */
+unsigned int land_generated = 0;
 
 /*
  * land variables
@@ -187,6 +189,9 @@ static void commodity_exchange_open( unsigned int wid )
    char **goods;
    int w, h;
 
+   /* Mark as generated. */
+   land_tabGenerate(LAND_WINDOW_COMMODITY);
+
    /* Get window dimensions. */
    window_dimWindow( wid, &w, &h );
 
@@ -566,6 +571,9 @@ static void bar_open( unsigned int wid )
 {
    int w, h, iw, ih, bw, bh, dh, th;
 
+   /* Mark as generated. */
+   land_tabGenerate(LAND_WINDOW_BAR);
+
    /* Set window functions. */
    window_onClose( wid, bar_close );
 
@@ -822,6 +830,9 @@ static void misn_open( unsigned int wid )
    int w, h;
    int y;
 
+   /* Mark as generated. */
+   land_tabGenerate(LAND_WINDOW_MISSION);
+
    /* Get window dimensions. */
    window_dimWindow( wid, &w, &h );
 
@@ -1180,6 +1191,9 @@ void land_genWindows( int load, int changetab )
    if (land_wid > 0) {
       land_regen = 2; /* Mark we're regenning. */
       window_destroy(land_wid);
+
+      /* Mark tabs as not generated. */
+      land_generated = 0;
    }
    land_loaded = 0;
 
@@ -1274,24 +1288,34 @@ void land_genWindows( int load, int changetab )
    }
 
    /* 4) Create other tabs. */
+#define should_open(s, w) \
+   (planet_hasService(land_planet, s) && (!land_tabGenerated(w)))
+
+   /* Things get a bit hairy here. Hooks may have triggered a GUI reload via
+    * e.g. player.swapShip, so the land tabs may have been generated already
+    * and we need to check that before regenerating them.
+    */
+
    /* Basic - bar + missions */
-   if (planet_hasService(land_planet, PLANET_SERVICE_BAR))
+   if (should_open( PLANET_SERVICE_BAR, LAND_WINDOW_BAR ))
       bar_open( land_getWid(LAND_WINDOW_BAR) );
-   if (planet_hasService(land_planet, PLANET_SERVICE_MISSIONS))
+   if (should_open( PLANET_SERVICE_MISSIONS, LAND_WINDOW_MISSION ))
       misn_open( land_getWid(LAND_WINDOW_MISSION) );
    /* Outfits. */
-   if (planet_hasService(land_planet, PLANET_SERVICE_OUTFITS))
+   if (should_open( PLANET_SERVICE_OUTFITS, LAND_WINDOW_OUTFITS ))
       outfits_open( land_getWid(LAND_WINDOW_OUTFITS) );
    /* Shipyard. */
-   if (planet_hasService(land_planet, PLANET_SERVICE_SHIPYARD))
+   if (should_open( PLANET_SERVICE_SHIPYARD, LAND_WINDOW_SHIPYARD ))
       shipyard_open( land_getWid(LAND_WINDOW_SHIPYARD) );
    /* Equipment. */
-   if (planet_hasService(land_planet, PLANET_SERVICE_OUTFITS) ||
-         planet_hasService(land_planet, PLANET_SERVICE_SHIPYARD))
+   if ((planet_hasService(land_planet, PLANET_SERVICE_OUTFITS) ||
+         planet_hasService(land_planet, PLANET_SERVICE_SHIPYARD)) &&
+         !land_tabGenerated( LAND_WINDOW_EQUIPMENT ))
       equipment_open( land_getWid(LAND_WINDOW_EQUIPMENT) );
    /* Commodity. */
-   if (planet_hasService(land_planet, PLANET_SERVICE_COMMODITY))
+   if (should_open( PLANET_SERVICE_COMMODITY, LAND_WINDOW_COMMODITY ))
       commodity_exchange_open( land_getWid(LAND_WINDOW_COMMODITY) );
+#undef should_open
 
    if (!regen) {
       /* Reset markers if needed. */
@@ -1689,6 +1713,7 @@ void land_cleanup (void)
    land_planet    = NULL;
    landed         = 0;
    land_visited   = 0;
+   land_generated = 0;
 
    /* Destroy window. */
    if (land_wid > 0)

src/land.h

@@ -46,6 +46,12 @@ extern int landed;
 extern Planet* land_planet;
 
 
+/* Tracking for which tabs have been generated. */
+#define land_tabGenerate(w)       (land_generated |= (1 << w)) /**< Mark tab generated. */
+#define land_tabGenerated(w)     (land_generated & (1 << w)) /**< Check if tab has been generated. */
+extern unsigned int land_generated;
+
+
 /*
  * Main interface.
  */

src/land_outfits.c

@@ -95,6 +95,9 @@ void outfits_open( unsigned int wid )
 {
    int w, h, iw, ih, bw, bh, off;
 
+   /* Mark as generated. */
+   land_tabGenerate(LAND_WINDOW_OUTFITS);
+
    /* Get dimensions. */
    outfits_getSize( wid, &w, &h, &iw, &ih, &bw, &bh );
 

src/land_shipyard.c

@@ -61,6 +61,9 @@ void shipyard_open( unsigned int wid )
    int y;
    const char *buf;
 
+   /* Mark as generated. */
+   land_tabGenerate(LAND_WINDOW_SHIPYARD);
+
    /* Init vars. */
    shipyard_selected = NULL;