From 6a1eea3982eca7c353244c4e804948fac7b225af Mon Sep 17 00:00:00 2001
From: Dennis Ushakov <dennis.ushakov@gmail.com>
Date: Wed, 23 May 2018 19:42:39 +0300
Subject: [PATCH] don't override namespaces explicitly declared in tag
 (WEB-31136)

---
 .../src/com/intellij/psi/impl/source/xml/XmlTagImpl.java         | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xml/xml-psi-impl/src/com/intellij/psi/impl/source/xml/XmlTagImpl.java b/xml/xml-psi-impl/src/com/intellij/psi/impl/source/xml/XmlTagImpl.java
index b6818d5c5980..bc96454abda4 100644
--- a/xml/xml-psi-impl/src/com/intellij/psi/impl/source/xml/XmlTagImpl.java
+++ b/xml/xml-psi-impl/src/com/intellij/psi/impl/source/xml/XmlTagImpl.java
@@ -915,6 +915,7 @@ public class XmlTagImpl extends XmlElementImpl implements XmlTag, HintedReferenc
             map = new BidirectionalMap<>();
           }
           for (final String[] prefix2ns : namespacesFromDocument) {
+            if (map.containsKey(prefix2ns[0])) continue;
             map.put(prefix2ns[0], getRealNs(prefix2ns[1]));
           }
         }