Added guards to prevent exceptions

resources/META-INF/plugin.xml

@@ -23,7 +23,7 @@
   <id>de.halirutan.mathematica</id>
   <name>Mathematica Support</name>
   <category>Custom Language</category>
-  <version>2.0.20</version>
+  <version>2.0.21</version>
   <idea-version since-build="163"/>
   <vendor email="[email protected]" url="http://mathematicaplugin.halirutan.de">Patrick Scheibe</vendor>
   <depends>com.intellij.modules.lang</depends>
@@ -67,13 +67,7 @@
       <i>New features and bug-fixes:</i>
       <br/>
       <ul>
-        <li>Improvement of syntax highlighting for full names of symbols inside scoping constructs (<a href="https://github.com/halirutan/Mathematica-IntelliJ-Plugin/issues/52">GH-52</a>)</li>
-        <li>Recognize function names in usage messages (<a href="https://github.com/halirutan/Mathematica-IntelliJ-Plugin/issues/58">GH-58</a>)</li>
-        <li>Improved highlighting settings colors (<a href="https://github.com/halirutan/Mathematica-IntelliJ-Plugin/issues/47">GH-47</a>)</li>
-        <li>Fixed smart-completion of Options that stopped working (<a href="https://github.com/halirutan/Mathematica-IntelliJ-Plugin/issues/30">GH-30</a>)</li>
-        <li>Fixed some localization constructs and added unicode of the Eth symbol (<a href="https://github.com/halirutan/Mathematica-IntelliJ-Plugin/issues/26">GH-26</a> and <a href="https://github.com/halirutan/Mathematica-IntelliJ-Plugin/issues/27">GH-27</a>)</li>
-        <li>Made indentation for Association brackets like the indentation for lists <a href="https://github.com/halirutan/Mathematica-IntelliJ-Plugin/issues/20">(GH-20)</a></li>
-        <li>Fixed the renaming engine so that renamed variables can now have context back-ticks</li>
+      <li>Added guard to fix exception (<a href="https://halirutan.myjetbrains.com/youtrack/issue/MMAP-88">MMAP-88</a>)</li>
       </ul>
     ]]>
   </change-notes>

src/de/halirutan/mathematica/codeinsight/completion/MathematicaCharFilter.java

@@ -38,6 +38,7 @@ public class MathematicaCharFilter extends CharFilter {
   @Nullable
   @Override
   public Result acceptChar(final char c, final int prefixLength, final Lookup lookup) {
+    if (!lookup.isCompletion()) return null;
     final PsiFile psiFile = lookup.getPsiFile();
     if (psiFile == null || !(psiFile.getFileType() instanceof MathematicaFileType)) {
       return null;

src/de/halirutan/mathematica/parsing/psi/MathematicaSymbolReferenceProvider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016 Patrick Scheibe
+ * Copyright (c) 2017 Patrick Scheibe
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
@@ -26,7 +26,6 @@
 import com.intellij.psi.PsiReferenceProvider;
 import com.intellij.util.ProcessingContext;
 import de.halirutan.mathematica.parsing.psi.api.Symbol;
-import de.halirutan.mathematica.parsing.psi.api.string.MString;
 import de.halirutan.mathematica.parsing.psi.impl.SymbolPsiReference;
 import org.jetbrains.annotations.NotNull;
 
@@ -42,7 +41,7 @@ public PsiReference[] getReferencesByElement(@NotNull PsiElement element, @NotNu
     if (!(element instanceof Symbol)) {
       return new PsiReference[0];
     }
-    ArrayList<PsiReference> result = new ArrayList<PsiReference>();
+    ArrayList<PsiReference> result = new ArrayList<>();
 
     Symbol symbol = (Symbol) element;
     final SymbolPsiReference reference = (SymbolPsiReference) symbol.getReference();
@@ -52,8 +51,10 @@ public PsiReference[] getReferencesByElement(@NotNull PsiElement element, @NotNu
       resolve = reference.resolve();
       if (resolve instanceof Symbol) {
         final PsiElement[] elemsReferencingToMe = ((Symbol) resolve).getElementsReferencingToMe();
-        for (PsiElement psiElement : elemsReferencingToMe) {
-          result.add(psiElement.getReference());
+        if (elemsReferencingToMe != null) {
+          for (PsiElement psiElement : elemsReferencingToMe) {
+            result.add(psiElement.getReference());
+          }
         }
       }
     }

src/de/halirutan/mathematica/parsing/psi/impl/SymbolImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013 Patrick Scheibe
+ * Copyright (c) 2017 Patrick Scheibe
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
@@ -168,6 +168,7 @@ public void addElementReferencingToMe(Symbol reference) {
 
   @Override
   public PsiElement[] getElementsReferencingToMe() {
+    if (myReferringElements.isEmpty()) return new PsiElement[0];
     return myReferringElements.toArray(new Symbol[myReferringElements.size()]);
   }