Use malloc instead of calloc to copy C strings

Improves benchmark by about 2%.

src/cmark.c

@@ -10,6 +10,15 @@ int cmark_version() { return CMARK_VERSION; }
 
 const char *cmark_version_string() { return CMARK_VERSION_STRING; }
 
+static void *xmalloc(size_t size) {
+  void *ptr = malloc(size);
+  if (!ptr) {
+    fprintf(stderr, "[cmark] malloc returned null pointer, aborting\n");
+    abort();
+  }
+  return ptr;
+}
+
 static void *xcalloc(size_t nmem, size_t size) {
   void *ptr = calloc(nmem, size);
   if (!ptr) {
@@ -28,7 +37,7 @@ static void *xrealloc(void *ptr, size_t size) {
   return new_ptr;
 }
 
-cmark_mem DEFAULT_MEM_ALLOCATOR = {xcalloc, xrealloc, free};
+cmark_mem DEFAULT_MEM_ALLOCATOR = {xmalloc, xcalloc, xrealloc, free};
 
 char *cmark_markdown_to_html(const char *text, size_t len, int options) {
   cmark_node *doc;

src/cmark.h

@@ -95,6 +95,7 @@ typedef struct cmark_iter cmark_iter;
  * when parsing and allocating a document tree
  */
 typedef struct cmark_mem {
+  void *(*malloc)(size_t);
   void *(*calloc)(size_t, size_t);
   void *(*realloc)(void *, size_t);
   void (*free)(void *);

src/inlines.c

@@ -99,8 +99,9 @@ static CMARK_INLINE cmark_node *make_simple(cmark_mem *mem, cmark_node_type t) {
 
 static cmark_node *make_str(subject *subj, int sc, int ec, cmark_chunk s) {
   cmark_node *e = make_literal(subj, CMARK_NODE_TEXT, sc, ec);
-  e->data = (unsigned char *)subj->mem->calloc(s.len + 1, 1);
+  e->data = (unsigned char *)subj->mem->malloc(s.len + 1);
   memcpy(e->data, s.data, s.len);
+  e->data[s.len] = 0;
   e->len = s.len;
   return e;
 }
@@ -133,7 +134,7 @@ static unsigned char *cmark_strdup(cmark_mem *mem, unsigned char *src) {
     return NULL;
   }
   size_t len = strlen((char *)src);
-  unsigned char *data = (unsigned char *)mem->calloc(len + 1, 1);
+  unsigned char *data = (unsigned char *)mem->malloc(len + 1);
   memcpy(data, src, len + 1);
   return data;
 }
@@ -870,8 +871,9 @@ static cmark_node *handle_pointy_brace(subject *subj, int options) {
     subj->pos += matchlen;
     cmark_node *node = make_literal(subj, CMARK_NODE_HTML_INLINE,
                                     subj->pos - matchlen - 1, subj->pos - 1);
-    node->data = (unsigned char *)subj->mem->calloc(len + 1, 1);
+    node->data = (unsigned char *)subj->mem->malloc(len + 1);
     memcpy(node->data, src, len);
+    node->data[len] = 0;
     node->len = len;
     adjust_subj_node_newlines(subj, node, matchlen, 1, options);
     return node;

src/node.c

@@ -254,8 +254,8 @@ static bufsize_t cmark_set_cstr(cmark_mem *mem, unsigned char **dst,
 
   if (src && src[0]) {
       len = (bufsize_t)strlen(src);
-      *dst = (unsigned char *)mem->calloc(len + 1, 1);
-      memcpy(*dst, src, len);
+      *dst = (unsigned char *)mem->malloc(len + 1);
+      memcpy(*dst, src, len + 1);
   } else {
       len = 0;
       *dst = NULL;