SculptMode fix:

DNA definition of Sculpt structs in Scene were not properly aligned,
causing memory errors on quit ("Memoryblock reconstruct: end corrupt").

More testing reveiled padding errors in two other DNA_ includes, for
sound and gamelogic. Both potentially crashers... and caused by
commenting out struct members with a C++ comment, that seems to not
work...

I've revived the DNA padding test method, which saves out a simple C
file you can compile to see where padding issues are. This now works
as follows:

- change line 991 in makesdna.c to become (1) (true).
- recompile makesdna.c
- you now have a padding.c in the same dir as makesdna.c
- compile it, command line: "gcc -o padding padding.c"
- now run it (./padding), and it will print out errors, if there are.

For me, the DNA files are now 100% padding free. Might be interesting to
check it in 64 bits though!

source/blender/makesdna/DNA_actuator_types.h

@@ -104,8 +104,6 @@ typedef struct bObjectActuator {
 	float loc[3], rot[3];
 	float dloc[3], drot[3];
 	float linearvelocity[3], angularvelocity[3];
-//	float addedlinearvelocity[3];
-//	char anotherpad[4];
 } bObjectActuator;
 
 typedef struct bIpoActuator {

source/blender/makesdna/DNA_scene_types.h

@@ -367,12 +367,14 @@ typedef struct BrushData
 	short size;
 	char strength, dir; /* Not used for smooth brush */
 	char airbrush;
-	char pad[7];
+	char pad[3];
 } BrushData;
 
 struct PropsetData;
 struct RenderInfo;
 struct SculptUndo;
+
+/* DNA WARNING: use of doubles forces SculptData internal alignment to 8 (only in gcc?) */
 typedef struct SculptData
 {
 	/* Cache of the OpenGL matrices */
@@ -396,10 +398,10 @@ typedef struct SculptData
 
 	struct PropsetData *propset;
 
-	struct SculptUndo *undo;
+	struct SculptUndo *undo, *padp;	/* pointer pad! */
 
 	/* For rotating around a pivot point */
-	vec3f pivot;
+	vec3f pivot, padv;				/* vec3f is 12 bytes */
 
 	/* Settings for each brush */
 	BrushData drawbrush, smoothbrush, pinchbrush, inflatebrush, grabbrush, layerbrush;
@@ -417,11 +419,11 @@ typedef struct SculptData
 	short texscale;
 	short texact, texnr;
 	short spacing;
-	char pad[2];
+	char pad;
 	char texrept;
 	char texfade;
 
-	char averaging, pad2[3];
+	char averaging;
 } SculptData;
 
 #define SCULPTREPT_DRAG 1

source/blender/makesdna/DNA_sound_types.h

@@ -103,8 +103,6 @@ typedef struct bSound {
 	float distance;
 	int flags;
 	int streamlen;
-//	unsigned int loopstart;
-//	unsigned int loopend;
 	char channels;
 	char highprio;
 	char pad[10];

source/blender/makesdna/intern/makesdna.c

@@ -141,7 +141,7 @@ int nr_structs=0;
 char **names, *namedata;		/* at adress names[a] is string a */
 char **types, *typedata;		/* at adress types[a] is string a */
 short *typelens;				/* at typelens[a] is de length of type a */
-short *alphalens;			    /* contains sizes as they are calculated on the alpha */
+short *alphalens;			    /* contains sizes as they are calculated on the DEC Alpha (64 bits) */
 short **structs, *structdata;	/* at sp= structs[a] is the first adress of a struct definition
 								   sp[0] is type number
 								   sp[1] is amount of elements
@@ -870,7 +870,7 @@ int make_structDNA(char *baseDirectory, FILE *file)
 	add_type("short", 2);	/* 2 */
 	add_type("ushort", 2);	/* 3 */
 	add_type("int", 4);		/* 4 */
-	add_type("long", 4);	/* 5 */
+	add_type("long", 4);	/* 5 */		/* should it be 8 on 64 bits? */
 	add_type("ulong", 4);	/* 6 */
 	add_type("float", 4);	/* 7 */
 	add_type("double", 8);	/* 8 */
@@ -988,7 +988,6 @@ int make_structDNA(char *baseDirectory, FILE *file)
 		dna_write(file, structs[0], len);
 	
 		/* a simple dna padding test */
-
 		if (0) {
 			FILE *fp;
 			int a;
@@ -999,16 +998,18 @@ int make_structDNA(char *baseDirectory, FILE *file)
 
 				// add all include files defined in the global array
 				for (i = 0; strlen(includefiles[i]); i++) {
-					fprintf(fp, "#include \"%s\"\n", includefiles[i]);
+					fprintf(fp, "#include \"%s%s\"\n", baseDirectory, includefiles[i]);
 				}
 
 				fprintf(fp, "main(){\n");
 				sp = typelens;
 				sp += firststruct;
 				for(a=firststruct; a<nr_types; a++, sp++) { 
-					fprintf(fp, "\tprintf(\" ");
-					fprintf(fp, "%%d %s %d ", types[a], *sp);
-					fprintf(fp, "\\n\",  sizeof(struct %s) - %d);\n", types[a], *sp);
+					if(*sp) {
+						fprintf(fp, "\tif(sizeof(struct %s) - %d) printf(\"ALIGN ERROR:", types[a], *sp);
+						fprintf(fp, "%%d %s %d ", types[a], *sp);
+						fprintf(fp, "\\n\",  sizeof(struct %s) - %d);\n", types[a], *sp);
+					}
 				}
 				fprintf(fp, "}\n");
 				fclose(fp);