Fix vec_pivot_m3, minor fixes for vecs of 0-size types

Improve some doc comments and includes

include/crater/hash.h

@@ -209,7 +209,7 @@ inline static void *cr8r_hash_next(cr8r_hashtbl_t *self, const cr8r_hashtbl_ft *
 	if(self->table_b){
 		if(cur){
 			b = (cur - self->table_b)/ft->base.size;
-			if(b++ >= self->len_b){
+			if(b++ >= self->len_b){// also goes to SEARCH_A if "b < 0" due to unsigned overflow wrapping
 				goto SEARCH_A;
 			}
 		}

src/lib/crater/prand.c

@@ -489,6 +489,7 @@ cr8r_prng *cr8r_prng_init_splitmix(uint64_t seed){
 	return res;
 }
 
+// need to create anonymous struct to statically allocate fla
 static struct{
 	uint64_t state_size;
 	uint32_t (*get_u32)(void*);

src/lib/crater/vec.c

@@ -45,7 +45,10 @@ void *cr8r_default_resize(cr8r_base_ft *base, void *p, uint64_t cap){
 		}
 		return NULL;
 	}
-	return p ? realloc(p, cap*base->size) : malloc(cap*base->size);
+	if(base->size){
+		return p ? realloc(p, cap*base->size) : malloc(cap*base->size);
+	}
+	return p;
 }
 
 void *cr8r_default_resize_pass(cr8r_base_ft *base, void *p, uint64_t cap){
@@ -208,7 +211,7 @@ void cr8r_vec_shuffle(cr8r_vec *self, cr8r_vec_ft *ft, cr8r_prng *prng){
 }
 
 static inline bool ensure_cap(cr8r_vec *self, cr8r_vec_ft *ft, uint64_t cap){
-	if(cap > self->cap && ft->base.size){
+	if(cap > self->cap){
 		uint64_t new_cap = ft->new_size(&ft->base, self->cap);
 		if(cap > new_cap){
 			new_cap = cap;
@@ -577,21 +580,24 @@ void *cr8r_vec_pivot_m3(const cr8r_vec *self, cr8r_vec_ft *ft, uint64_t a, uint6
 		return NULL;
 	}
 	void *fst = self->buf + a*ft->base.size;
+	if(b - a < 3){
+		return fst;
+	}
 	void *lst = self->buf + (b - 1)*ft->base.size;
 	void *mid = self->buf + (a + b - 1)/2*ft->base.size;
 	int ord = ft->cmp(&ft->base, fst, mid);
 	int sorted;
-	if(!ord){
+	if(!ord){// if *fst == *mid, then both are valid pivots regardless of *lst
 		return mid;
-	}else if((sorted = ord*ft->cmp(&ft->base, mid, lst))){
-		if(sorted > 0){
+	}else if((sorted = ord*ft->cmp(&ft->base, mid, lst))){// multiplying the ord of *mid and *lst by the ord of *fst and *mid lets us easily detect if the sequence is monotonic
+		if(sorted > 0){// in this case, either *fst < *mid < *lst OR *fst > *mid > *lst
 			return mid;
-		}else if(ft->cmp(&ft->base, lst, fst)*ord >= 0){
+		}else if(ft->cmp(&ft->base, lst, fst)*ord >= 0){// if sorted < 0, *mid is either the max or min, determined by ord (the comparison between *fst and *mid)
+			return fst;// if the ord of *fst and *mid is the same as the ord of *lst and *fst, then either *lst < *fst < *mid or *lst > *fst > *mid.  Alternatively, if *lst == *fst, ten both are valid pivots
+		}else{// otherwise, *fst is either the max or min, but *mid is also either the max or min, and since none of the three are equal in this case, we can conclude tht *lst is the median
 			return lst;
-		}else{
-			return fst;
 		}
-	}else{
+	}else{// if *fst != *mid but *mid == *lst, then both mid and lst are valid pivots regardless of *fst
 		return mid;
 	}
 }

src/test/dlog_t64.c

@@ -1,8 +1,8 @@
-#include "crater/container.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#include <crater/container.h>
 #include <crater/prand.h>
 
 const uint64_t gs[4] = {1, (1ull << 63) + 3, (1ull << 63) - 1, -1};

src/test/minmax_heap.c

@@ -1,4 +1,3 @@
-#include "crater/container.h"
 #include "crater/vec.h"
 #include <stdio.h>
 #include <stdlib.h>

src/test/pandigital_primes.c

@@ -1,5 +1,4 @@
 //This test is based on Project Euler 41
-#include "crater/container.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

src/test/pointcloud.c

@@ -1,10 +1,10 @@
-#include "crater/kd_check.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <inttypes.h>
 #include <math.h>
 
+#include <crater/kd_check.h>
 #include <crater/kd_tree.h>
 
 int main(){

src/test/vec_bsearch.c

@@ -1,4 +1,3 @@
-#include "crater/container.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

src/test/vec_oom.c

@@ -1,13 +1,17 @@
 #define _GNU_SOURCE
-#include "crater/container.h"
-#include "crater/vec.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <inttypes.h>
 
+#include <crater/vec.h>
 #include <crater/minmax_heap.h>
 
+const char *__asan_default_options(){
+	return "detect_leaks=0";
+	// there is a bogus leak that asan finds but valgrind doesn't
+}
+
 inline static void default_copy(cr8r_base_ft *ft, void *dest, const void *src){
 	memcpy(dest, src, ft->size);
 }

src/test/wc.c

@@ -1,5 +1,4 @@
 #define _POSIX_C_SOURCE 200809L
-#include "crater/container.h"
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>