From def53fd73f01663e6d8a42663e01d7f9f13e5356 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Fri, 12 Mar 2021 17:05:26 +0200
Subject: [PATCH] os: prevent os.exists_in_system_path() from panicing

---
 vlib/os/os.v      | 3 +++
 vlib/os/os_test.v | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/vlib/os/os.v b/vlib/os/os.v
index ed5009c4f8..3399c3ecff 100644
--- a/vlib/os/os.v
+++ b/vlib/os/os.v
@@ -375,6 +375,9 @@ fn executable_fallback() string {
 // find_exe_path walks the environment PATH, just like most shell do, it returns
 // the absolute path of the executable if found
 pub fn find_abs_path_of_executable(exepath string) ?string {
+	if exepath == '' {
+		return error('expected non empty `exepath`')
+	}
 	if is_abs_path(exepath) {
 		return real_path(exepath)
 	}
diff --git a/vlib/os/os_test.v b/vlib/os/os_test.v
index cface1ebf7..b055263f74 100644
--- a/vlib/os/os_test.v
+++ b/vlib/os/os_test.v
@@ -543,3 +543,12 @@ fn test_posix_set_bit() {
 		rm(fpath) or {}
 	}
 }
+
+fn test_exists_in_system_path() {
+	assert os.exists_in_system_path('') == false
+	$if windows {
+		assert os.exists_in_system_path('cmd') == true
+		return
+	}
+	assert os.exists_in_system_path('ls') == true
+}