From d149ceef4a3549ddd2a3267ec160bab1d9f939e8 Mon Sep 17 00:00:00 2001
From: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Date: Thu, 4 Jul 2013 10:40:57 +0200
Subject: [PATCH] VPATH resolution: don't crash when $(FOO) expands to nothing

Task-number: QTBUG-29988
Change-Id: Ice3dc28002fc70e70fecc5d61bd0b32260ac0d50
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
---
 qmake/generators/makefile.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/qmake/generators/makefile.cpp b/qmake/generators/makefile.cpp
index d095bdf83df..f65f98f42ba 100644
--- a/qmake/generators/makefile.cpp
+++ b/qmake/generators/makefile.cpp
@@ -317,6 +317,10 @@ MakefileGenerator::findFilesInVPATH(ProStringList l, uchar flags, const QString
         if(!val.isEmpty()) {
             QString qval = val.toQString();
             QString file = fixEnvVariables(qval);
+            if (file.isEmpty()) {
+                ++val_it;
+                continue;
+            }
             if(!(flags & VPATH_NoFixify))
                 file = fileFixify(file, qmake_getpwd(), Option::output_dir);
             if (file.at(0) == '\"' && file.at(file.length() - 1) == '\"')