builtins: print setup info if repo is found

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -1062,6 +1062,7 @@ __attribute__((format (printf, 1, 2)))
 extern void trace_printf(const char *format, ...);
 __attribute__((format (printf, 2, 3)))
 extern void trace_argv_printf(const char **argv, const char *format, ...);
+extern void trace_repo_setup(const char *prefix);
 
 /* convert.c */
 /* returns 1 if *dst was used */

git.c

@@ -264,6 +264,10 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 			use_pager = check_pager_config(p->cmd);
 		if (use_pager == -1 && p->option & USE_PAGER)
 			use_pager = 1;
+
+		if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
+		    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
+			trace_repo_setup(prefix);
 	}
 	commit_pager_choice();
 

trace.c

@@ -131,3 +131,45 @@ void trace_argv_printf(const char **argv, const char *fmt, ...)
 	if (need_close)
 		close(fd);
 }
+
+static const char *quote_crnl(const char *path)
+{
+	static char new_path[PATH_MAX];
+	const char *p2 = path;
+	char *p1 = new_path;
+
+	if (!path)
+		return NULL;
+
+	while (*p2) {
+		switch (*p2) {
+		case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
+		case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
+		case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
+		default:
+			*p1++ = *p2;
+		}
+		p2++;
+	}
+	*p1 = '\0';
+	return new_path;
+}
+
+/* FIXME: move prefix to startup_info struct and get rid of this arg */
+void trace_repo_setup(const char *prefix)
+{
+	char cwd[PATH_MAX];
+	char *trace = getenv("GIT_TRACE");
+
+	if (!trace || !strcmp(trace, "") ||
+	    !strcmp(trace, "0") || !strcasecmp(trace, "false"))
+		return;
+
+	if (!getcwd(cwd, PATH_MAX))
+		die("Unable to get current working directory");
+
+	trace_printf("setup: git_dir: %s\n", quote_crnl(get_git_dir()));
+	trace_printf("setup: worktree: %s\n", quote_crnl(get_git_work_tree()));
+	trace_printf("setup: cwd: %s\n", quote_crnl(cwd));
+	trace_printf("setup: prefix: %s\n", quote_crnl(prefix));
+}