puzzles: add more parameter validation checks

Fixes some annoying crashes.

Change-Id: If3c293bd90e301c3e697d1e5fcb1b0aa2ea320fb

apps/plugins/puzzles/src/blackbox.c

@@ -200,6 +200,8 @@ static char *validate_params(const game_params *params, int full)
         return "Minimum number of balls may not be greater than maximum";
     if (params->minballs >= params->w * params->h)
         return "Too many balls to fit in grid";
+    if (params->minballs < 1)
+        return "Number of balls must be at least one";
     return NULL;
 }
 

apps/plugins/puzzles/src/flood.c

@@ -213,8 +213,10 @@ static game_params *custom_params(const config_item *cfg)
 
 static char *validate_params(const game_params *params, int full)
 {
-    if (params->w < 2 && params->h < 2)
+    if (params->w * params->h < 2)
         return "Grid must contain at least two squares";
+    if (params->w < 1 || params->h < 1)
+        return "Width and height must both be at least one";
     if (params->colours < 3 || params->colours > 10)
         return "Must have between 3 and 10 colours";
     if (params->leniency < 0)

apps/plugins/puzzles/src/mines.c

@@ -265,6 +265,8 @@ static char *validate_params(const game_params *params, int full)
 	return "Width and height must both be greater than two";
     if (params->n > params->w * params->h - 9)
 	return "Too many mines for grid size";
+    if (params->n < 1)
+        return "Number of mines must be greater than zero";
 
     /*
      * FIXME: Need more constraints here. Not sure what the

apps/plugins/puzzles/src/netslide.c

@@ -320,6 +320,8 @@ static char *validate_params(const game_params *params, int full)
 	return "Barrier probability may not be negative";
     if (params->barrier_probability > 1)
 	return "Barrier probability may not be greater than 1";
+    if (params->movetarget < 0)
+        return "Number of shuffling moves may not be negative";
     return NULL;
 }
 

apps/plugins/puzzles/src/pattern.c

@@ -179,6 +179,8 @@ static char *validate_params(const game_params *params, int full)
 {
     if (params->w <= 0 || params->h <= 0)
 	return "Width and height must both be greater than zero";
+    if (params->w * params->w < 2)
+        return "Grid must contain at least two squares";
     return NULL;
 }
 

apps/plugins/puzzles/src/sixteen.c

@@ -178,7 +178,8 @@ static char *validate_params(const game_params *params, int full)
 {
     if (params->w < 2 || params->h < 2)
 	return "Width and height must both be at least two";
-
+    if (params->movetarget < 0)
+        return "Number of shuffling moves may not be negative";
     return NULL;
 }
 

apps/plugins/puzzles/src/twiddle.c

@@ -217,6 +217,8 @@ static char *validate_params(const game_params *params, int full)
 	return "Width must be at least the rotating block size";
     if (params->h < params->n)
 	return "Height must be at least the rotating block size";
+    if (params->movetarget < 0)
+        return "Number of shuffling moves may not be negative";
     return NULL;
 }