Fix: Protect against a few out of bounds or uninitialised usage errors

src/newgrf_spritegroup.cpp

@@ -154,6 +154,7 @@ static uint32 RotateRight(uint32 val, uint32 rot)
 {
 	/* Do not rotate more than necessary */
 	rot %= 32;
+	assert(rot > 0);
 
 	return (val >> rot) | (val << (32 - rot));
 }

src/pathfinder/opf/opf_ship.cpp

@@ -145,6 +145,7 @@ static uint FindShipTrack(const Ship *v, TileIndex tile, DiagDirection dir, Trac
 
 	Track best_track = INVALID_TRACK;
 
+	assert(bits != TRACK_BIT_NONE);
 	do {
 		Track i = RemoveFirstTrack(&bits);
 
@@ -176,7 +177,7 @@ good:;
 		best_length = pfs.best_length;
 bad:;
 
-	} while (bits != 0);
+	} while (bits != TRACK_BIT_NONE);
 
 	*track = best_track;
 	return best_bird_dist;

src/pathfinder/yapf/yapf_rail.cpp

@@ -28,6 +28,8 @@ template <typename Tpf> void DumpState(Tpf &pf1, Tpf &pf2)
 	pf2.DumpBase(dmp2);
 	FILE *f1 = fopen("yapf1.txt", "wt");
 	FILE *f2 = fopen("yapf2.txt", "wt");
+	assert(f1 != NULL);
+	assert(f2 != NULL);
 	fwrite(dmp1.m_out.Data(), 1, dmp1.m_out.Size(), f1);
 	fwrite(dmp2.m_out.Data(), 1, dmp2.m_out.Size(), f2);
 	fclose(f1);

src/road_map.h

@@ -449,6 +449,7 @@ enum Roadside {
 	ROADSIDE_GRASS            = 1, ///< Road on grass
 	ROADSIDE_PAVED            = 2, ///< Road with paved sidewalks
 	ROADSIDE_STREET_LIGHTS    = 3, ///< Road with street lights on paved sidewalks
+	// 4 is unused for historical reasons
 	ROADSIDE_TREES            = 5, ///< Road with trees on paved sidewalks
 	ROADSIDE_GRASS_ROAD_WORKS = 6, ///< Road on grass with road works
 	ROADSIDE_PAVED_ROAD_WORKS = 7, ///< Road with sidewalks and road works

src/settingsgen/settingsgen.cpp

@@ -371,7 +371,10 @@ static bool CompareFiles(const char *n1, const char *n2)
 	if (f2 == NULL) return false;
 
 	FILE *f1 = fopen(n1, "rb");
-	if (f1 == NULL) error("can't open %s", n1);
+	if (f1 == NULL) {
+		fclose(f2);
+		error("can't open %s", n1);
+	}
 
 	size_t l1, l2;
 	do {

src/strgen/strgen.cpp

@@ -215,7 +215,10 @@ bool CompareFiles(const char *n1, const char *n2)
 	if (f2 == NULL) return false;
 
 	FILE *f1 = fopen(n1, "rb");
-	if (f1 == NULL) error("can't open %s", n1);
+	if (f1 == NULL) {
+		fclose(f2);
+		error("can't open %s", n1);
+	}
 
 	size_t l1, l2;
 	do {

src/town_cmd.cpp

@@ -719,7 +719,7 @@ void UpdateTownCargoTotal(Town *t)
 static void UpdateTownCargoes(Town *t, TileIndex start, bool update_total = true)
 {
 	CargoArray accepted, produced;
-	CargoTypes dummy;
+	CargoTypes dummy = 0;
 
 	/* Gather acceptance for all houses in an area around the start tile.
 	 * The area is composed of the square the tile is in, extended one square in all

src/track_func.h

@@ -61,7 +61,7 @@ static inline bool IsValidTrackdirForRoadVehicle(Trackdir trackdir)
  */
 static inline bool IsValidTrackdir(Trackdir trackdir)
 {
-	return (1 << trackdir & TRACKDIR_BIT_MASK) != TRACKDIR_BIT_NONE;
+	return trackdir != INVALID_TRACKDIR && ((1 << trackdir & TRACKDIR_BIT_MASK) != TRACKDIR_BIT_NONE);
 }
 
 /**

src/window.cpp

@@ -938,6 +938,8 @@ static void DrawOverlappedWindow(Window *w, int left, int top, int right, int bo
 void DrawOverlappedWindowForAll(int left, int top, int right, int bottom)
 {
 	Window *w;
+
+	DrawPixelInfo *old_dpi = _cur_dpi;
 	DrawPixelInfo bk;
 	_cur_dpi = &bk;
 
@@ -951,6 +953,7 @@ void DrawOverlappedWindowForAll(int left, int top, int right, int bottom)
 			DrawOverlappedWindow(w, max(left, w->left), max(top, w->top), min(right, w->left + w->width), min(bottom, w->top + w->height));
 		}
 	}
+	_cur_dpi = old_dpi;
 }
 
 /**