From 7d4d25353c1e36a97959f44ed909f80f92b61744 Mon Sep 17 00:00:00 2001
From: Alexander Neumann <30894796+Neumann-A@users.noreply.github.com>
Date: Fri, 13 Nov 2020 15:14:15 +0100
Subject: [PATCH] ninjabackend: fix matching of empty strings

closes #7977
---
 mesonbuild/backend/ninjabackend.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index daada12b2..1ed742b75 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -266,7 +266,7 @@ class NinjaRule:
         # expand variables in command
         command = ' '.join([self._quoter(x) for x in self.command + self.args])
         estimate = len(command)
-        for m in re.finditer(r'(\${\w*}|\$\w*)?[^$]*', command):
+        for m in re.finditer(r'(\${\w+}|\$\w+)?[^$]*', command):
             if m.start(1) != -1:
                 estimate -= m.end(1) - m.start(1) + 1
                 chunk = m.group(1)