diff --git a/builtin/apply.c b/builtin/apply.c
index 5fd099ed40..9f8f5bac07 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -2867,9 +2867,7 @@ static int apply_binary_fragment(struct image *img, struct patch *patch)
 	case BINARY_LITERAL_DEFLATED:
 		clear_image(img);
 		img->len = fragment->size;
-		img->buf = xmalloc(img->len+1);
-		memcpy(img->buf, fragment->patch, img->len);
-		img->buf[img->len] = '\0';
+		img->buf = xmemdupz(fragment->patch, img->len);
 		return 0;
 	}
 	return -1;
diff --git a/builtin/blame.c b/builtin/blame.c
index c59e702021..32ce05f615 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -2707,11 +2707,8 @@ parse_done:
 		die("revision walk setup failed");
 
 	if (is_null_sha1(sb.final->object.sha1)) {
-		char *buf;
 		o = sb.final->util;
-		buf = xmalloc(o->file.size + 1);
-		memcpy(buf, o->file.ptr, o->file.size + 1);
-		sb.final_buf = buf;
+		sb.final_buf = xmemdupz(o->file.ptr, o->file.size);
 		sb.final_buf_size = o->file.size;
 	}
 	else {
diff --git a/builtin/clean.c b/builtin/clean.c
index 27701d222c..1032563e5f 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -621,8 +621,7 @@ static int *list_and_choose(struct menu_opts *opts, struct menu_stuff *stuff)
 				nr += chosen[i];
 		}
 
-		result = xmalloc(sizeof(int) * (nr + 1));
-		memset(result, 0, sizeof(int) * (nr + 1));
+		result = xcalloc(nr + 1, sizeof(int));
 		for (i = 0; i < stuff->nr && j < nr; i++) {
 			if (chosen[i])
 				result[j++] = i;
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index fc40411892..5568a5bc3b 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -362,8 +362,7 @@ static void set_thread_data(struct thread_local *data)
 
 static struct base_data *alloc_base_data(void)
 {
-	struct base_data *base = xmalloc(sizeof(struct base_data));
-	memset(base, 0, sizeof(*base));
+	struct base_data *base = xcalloc(1, sizeof(struct base_data));
 	base->ref_last = -1;
 	base->ofs_last = -1;
 	return base;
diff --git a/compat/mingw.c b/compat/mingw.c
index c19e3d954b..9d435e2cf4 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1316,8 +1316,7 @@ static int WSAAPI getaddrinfo_stub(const char *node, const char *service,
 	else
 		ai->ai_canonname = NULL;
 
-	sin = xmalloc(ai->ai_addrlen);
-	memset(sin, 0, ai->ai_addrlen);
+	sin = xcalloc(1, ai->ai_addrlen);
 	sin->sin_family = AF_INET;
 	/* Note: getaddrinfo is supposed to allow service to be a string,
 	 * which should be looked up using getservbyname. This is
diff --git a/connect.c b/connect.c
index 37ff018f13..5047402a1a 100644
--- a/connect.c
+++ b/connect.c
@@ -64,9 +64,7 @@ static void parse_one_symref_info(struct string_list *symref, const char *val, i
 	if (!len)
 		return; /* just "symref" */
 	/* e.g. "symref=HEAD:refs/heads/master" */
-	sym = xmalloc(len + 1);
-	memcpy(sym, val, len);
-	sym[len] = '\0';
+	sym = xmemdupz(val, len);
 	target = strchr(sym, ':');
 	if (!target)
 		/* just "symref=something" */
diff --git a/http-backend.c b/http-backend.c
index 57290d9bda..80790bbaef 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -610,9 +610,7 @@ int main(int argc, char **argv)
 
 			cmd = c;
 			n = out[0].rm_eo - out[0].rm_so;
-			cmd_arg = xmalloc(n);
-			memcpy(cmd_arg, dir + out[0].rm_so + 1, n-1);
-			cmd_arg[n-1] = '\0';
+			cmd_arg = xmemdupz(dir + out[0].rm_so + 1, n - 1);
 			dir[out[0].rm_so] = 0;
 			break;
 		}
diff --git a/path.c b/path.c
index bc804a31b3..25c3b8ba7e 100644
--- a/path.c
+++ b/path.c
@@ -249,9 +249,7 @@ int validate_headref(const char *path)
 static struct passwd *getpw_str(const char *username, size_t len)
 {
 	struct passwd *pw;
-	char *username_z = xmalloc(len + 1);
-	memcpy(username_z, username, len);
-	username_z[len] = '\0';
+	char *username_z = xmemdupz(username, len);
 	pw = getpwnam(username_z);
 	free(username_z);
 	return pw;
diff --git a/pathspec.c b/pathspec.c
index 89f2c8ffff..9304ee33d7 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -389,8 +389,7 @@ void parse_pathspec(struct pathspec *pathspec,
 		if (!(flags & PATHSPEC_PREFER_CWD))
 			die("BUG: PATHSPEC_PREFER_CWD requires arguments");
 
-		pathspec->items = item = xmalloc(sizeof(*item));
-		memset(item, 0, sizeof(*item));
+		pathspec->items = item = xcalloc(1, sizeof(*item));
 		item->match = prefix;
 		item->original = prefix;
 		item->nowildcard_len = item->len = strlen(prefix);
diff --git a/sh-i18n--envsubst.c b/sh-i18n--envsubst.c
index 855d28cf94..6dd03a974a 100644
--- a/sh-i18n--envsubst.c
+++ b/sh-i18n--envsubst.c
@@ -278,9 +278,7 @@ static string_list_ty variables_set;
 static void
 note_variable (const char *var_ptr, size_t var_len)
 {
-  char *string = xmalloc (var_len + 1);
-  memcpy (string, var_ptr, var_len);
-  string[var_len] = '\0';
+  char *string = xmemdupz (var_ptr, var_len);
 
   string_list_append (&variables_set, string);
 }