Merge branch 'jk/bug-to-abort' into maint

Introduce the BUG() macro to improve die("BUG: ...").

* jk/bug-to-abort:
  usage: add NORETURN to BUG() function definitions
  config: complain about --local outside of a git repo
  setup_git_env: convert die("BUG") to BUG()
  usage.c: add BUG() function

builtin/config.c

@@ -496,6 +496,9 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		usage_with_options(builtin_config_usage, builtin_config_options);
 	}
 
+	if (use_local_config && nongit)
+		die(_("--local can only be used inside a git repository"));
+
 	if (given_config_source.file &&
 			!strcmp(given_config_source.file, "-")) {
 		given_config_source.file = NULL;

environment.c

@@ -169,7 +169,7 @@ static void setup_git_env(void)
 	git_dir = getenv(GIT_DIR_ENVIRONMENT);
 	if (!git_dir) {
 		if (!startup_info->have_repository)
-			die("BUG: setup_git_env called without repository");
+			BUG("setup_git_env called without repository");
 		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 	}
 	gitfile = read_gitfile(git_dir);

git-compat-util.h

@@ -1064,6 +1064,15 @@ static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
 #define HAVE_VARIADIC_MACROS 1
 #endif
 
+#ifdef HAVE_VARIADIC_MACROS
+__attribute__((format (printf, 3, 4))) NORETURN
+void BUG_fl(const char *file, int line, const char *fmt, ...);
+#define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
+#else
+__attribute__((format (printf, 1, 2))) NORETURN
+void BUG(const char *fmt, ...);
+#endif
+
 /*
  * Preserves errno, prints a message, but gives no warning for ENOENT.
  * Returns 0 on success, which includes trying to unlink an object that does

t/t1300-repo-config.sh

@@ -1539,4 +1539,10 @@ test_expect_success !MINGW '--show-origin blob ref' '
 	test_cmp expect output
 '
 
+test_expect_success '--local requires a repo' '
+	# we expect 128 to ensure that we do not simply
+	# fail to find anything and return code "1"
+	test_expect_code 128 nongit git config --local foo.bar
+'
+
 test_done

usage.c

@@ -201,3 +201,35 @@ void warning(const char *warn, ...)
 	warn_routine(warn, params);
 	va_end(params);
 }
+
+static NORETURN void BUG_vfl(const char *file, int line, const char *fmt, va_list params)
+{
+	char prefix[256];
+
+	/* truncation via snprintf is OK here */
+	if (file)
+		snprintf(prefix, sizeof(prefix), "BUG: %s:%d: ", file, line);
+	else
+		snprintf(prefix, sizeof(prefix), "BUG: ");
+
+	vreportf(prefix, fmt, params);
+	abort();
+}
+
+#ifdef HAVE_VARIADIC_MACROS
+NORETURN void BUG_fl(const char *file, int line, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	BUG_vfl(file, line, fmt, ap);
+	va_end(ap);
+}
+#else
+NORETURN void BUG(const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	BUG_vfl(NULL, 0, fmt, ap);
+	va_end(ap);
+}
+#endif