Don't complete keywords for upper case prefix

idea/src/org/jetbrains/jet/plugin/completion/JetKeywordCompletionContributor.java

@@ -221,7 +221,7 @@ public class JetKeywordCompletionContributor extends CompletionContributor {
 
         @Override
         public boolean prefixMatches(@NotNull String name) {
-            return StringUtil.startsWithIgnoreCase(name, getPrefix());
+            return StringUtil.startsWith(name, getPrefix());
         }
 
         @NotNull

idea/testData/completion/keywords/NoCompletionForCapitalPrefix.kt

@@ -0,0 +1,3 @@
+P<caret>
+
+// ABSENT: public, private, protected

idea/tests/org/jetbrains/jet/completion/KeywordsCompletionTest.java

@@ -119,6 +119,10 @@ public class KeywordsCompletionTest extends JetCompletionTestBase {
         doTest();
     }
 
+    public void testNoCompletionForCapitalPrefix() {
+        doTest();
+    }
+
     public void testPropertySetterGetter() {
         doTest();
     }