Merge branch 'jk/tighten-alloc' into maint

* jk/tighten-alloc: (23 commits)
  compat/mingw: brown paper bag fix for 50a6c8e
  ewah: convert to REALLOC_ARRAY, etc
  convert ewah/bitmap code to use xmalloc
  diff_populate_gitlink: use a strbuf
  transport_anonymize_url: use xstrfmt
  git-compat-util: drop mempcpy compat code
  sequencer: simplify memory allocation of get_message
  test-path-utils: fix normalize_path_copy output buffer size
  fetch-pack: simplify add_sought_entry
  fast-import: simplify allocation in start_packfile
  write_untracked_extension: use FLEX_ALLOC helper
  prepare_{git,shell}_cmd: use argv_array
  use st_add and st_mult for allocation size computation
  convert trivial cases to FLEX_ARRAY macros
  use xmallocz to avoid size arithmetic
  convert trivial cases to ALLOC_ARRAY
  convert manual allocations to argv_array
  argv-array: add detach function
  add helpers for allocating flex-array structs
  harden REALLOC_ARRAY and xcalloc against size_t overflow
  ...

compat/mingw.c

@@ -769,7 +769,7 @@ static const char *quote_arg(const char *arg)
 		return arg;
 
 	/* insert \ where necessary */
-	d = q = xmalloc(len+n+3);
+	d = q = xmalloc(st_add3(len, n, 3));
 	*d++ = '"';
 	while (*arg) {
 		if (*arg == '"')
@@ -852,7 +852,7 @@ static char **get_path_split(void)
 	if (!n)
 		return NULL;
 
-	path = xmalloc((n+1)*sizeof(char *));
+	ALLOC_ARRAY(path, n + 1);
 	p = envpath;
 	i = 0;
 	do {
@@ -937,7 +937,7 @@ static wchar_t *make_environment_block(char **deltaenv)
 		i++;
 
 	/* copy the environment, leaving space for changes */
-	tmpenv = xmalloc((size + i) * sizeof(char*));
+	ALLOC_ARRAY(tmpenv, size + i);
 	memcpy(tmpenv, environ, size * sizeof(char*));
 
 	/* merge supplied environment changes into the temporary environment */
@@ -1028,7 +1028,7 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 			free(quoted);
 	}
 
-	wargs = xmalloc((2 * args.len + 1) * sizeof(wchar_t));
+	ALLOC_ARRAY(wargs, st_add(st_mult(2, args.len), 1));
 	xutftowcs(wargs, args.buf, 2 * args.len + 1);
 	strbuf_release(&args);
 
@@ -1127,7 +1127,7 @@ static int try_shell_exec(const char *cmd, char *const *argv)
 		int argc = 0;
 		const char **argv2;
 		while (argv[argc]) argc++;
-		argv2 = xmalloc(sizeof(*argv) * (argc+1));
+		ALLOC_ARRAY(argv2, argc + 1);
 		argv2[0] = (char *)cmd;	/* full path to the script file */
 		memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
 		pid = mingw_spawnv(prog, argv2, 1);

compat/qsort.c

@@ -47,7 +47,7 @@ static void msort_with_tmp(void *b, size_t n, size_t s,
 void git_qsort(void *b, size_t n, size_t s,
 	       int (*cmp)(const void *, const void *))
 {
-	const size_t size = n * s;
+	const size_t size = st_mult(n, s);
 	char buf[1024];
 
 	if (size < sizeof(buf)) {

compat/setenv.c

@@ -18,7 +18,7 @@ int gitsetenv(const char *name, const char *value, int replace)
 
 	namelen = strlen(name);
 	valuelen = strlen(value);
-	envstr = malloc((namelen + valuelen + 2));
+	envstr = malloc(st_add3(namelen, valuelen, 2));
 	if (!envstr) {
 		errno = ENOMEM;
 		return -1;

compat/win32/syslog.c

@@ -32,7 +32,7 @@ void syslog(int priority, const char *fmt, ...)
 		return;
 	}
 
-	str = malloc(str_len + 1);
+	str = malloc(st_add(str_len, 1));
 	if (!str) {
 		warning("malloc failed: '%s'", strerror(errno));
 		return;
@@ -43,7 +43,7 @@ void syslog(int priority, const char *fmt, ...)
 	va_end(ap);
 
 	while ((pos = strstr(str, "%1")) != NULL) {
-		str = realloc(str, ++str_len + 1);
+		str = realloc(str, st_add(++str_len, 1));
 		if (!str) {
 			warning("realloc failed: '%s'", strerror(errno));
 			return;