Ensure QMAKE_PRL_LIBS is a unique list.

Windows static builds currently fail due to overlong command
link lines containing multiple occurrences of base libraries.

Task-number: QTBUG-28131
Change-Id: Ibf7f551fc98c879111b32b27a16f4e96260743c7
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/qmake/meta.cpp b/qmake/meta.cpp
index 2a0614a9bc..e1029ffcb0 100644
--- a/qmake/meta.cpp
+++ b/qmake/meta.cpp
@@ -187,7 +187,11 @@ QMakeMetaInfo::readLibtoolFile(const QString &f)
                         (*lit) = conf->first("QMAKE_LFLAGS_RPATH") + (*lit).mid(2);
                 }
             }
-            vars["QMAKE_PRL_LIBS"] += lst;
+            ProStringList &prlLibs = vars["QMAKE_PRL_LIBS"];
+            foreach (const ProString &s, lst) {
+                prlLibs.removeAll(s);
+                prlLibs.append(s);
+            }
         }
     }
     return true;