goto popups: name should be above _name

java/java-tests/testSrc/com/intellij/navigation/ChooseByNameTest.groovy

@@ -65,6 +65,17 @@ class Impl extends Intf {
     assert !(impl.findMethodsByName('xxx1', false)[0] in elements)
   }
 
+  public void "test disprefer underscore"() {
+    def intf = myFixture.addClass("""
+class Intf {
+  void _xxx1() {}
+  void xxx2() {}
+}""")
+
+    def elements = getPopupElements(new GotoSymbolModel2(project), "xxx")
+    assert elements == [intf.findMethodsByName('xxx2', false), ChooseByNameBase.NON_PREFIX_SEPARATOR, intf.findMethodsByName('_xxx1', false)]
+  }
+
   private List<Object> getPopupElements(ChooseByNameModel model, String text) {
     return getPopupElements(createPopup(model), text)
   }

platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CamelHumpMatcher.java

@@ -5,13 +5,13 @@ import com.intellij.codeInsight.CodeInsightSettings;
 import com.intellij.codeInsight.completion.PrefixMatcher;
 import com.intellij.codeInsight.lookup.LookupElement;
 import com.intellij.openapi.Disposable;
-import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.util.Disposer;
+import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.registry.Registry;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.codeStyle.MinusculeMatcher;
 import com.intellij.psi.codeStyle.NameUtil;
-import com.intellij.util.containers.ContainerUtil;
+import com.intellij.util.containers.FList;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.TestOnly;
 
@@ -43,12 +43,24 @@ public class CamelHumpMatcher extends PrefixMatcher {
 
   @Override
   public boolean isStartMatch(LookupElement element) {
-    return ContainerUtil.or(element.getAllLookupStrings(), new Condition<String>() {
-      @Override
-      public boolean value(String s) {
-        return myCaseInsensitiveMatcher.isStartMatch(s);
+    for (String s : element.getAllLookupStrings()) {
+      FList<TextRange> ranges = myCaseInsensitiveMatcher.matchingFragments(s);
+      if (ranges == null) continue;
+      if (ranges.isEmpty() || isStartMatchModuloUnderscores(s, ranges.get(0).getStartOffset())) {
+        return true;
       }
-    });
+    }
+
+    return false;
+  }
+
+  private static boolean isStartMatchModuloUnderscores(@NotNull String name, int startIndex) {
+    for (int i = 0; i < startIndex; i++) {
+      if (name.charAt(i) != '_') {
+        return false;
+      }
+    }
+    return true;
   }
 
   @Override

platform/util/src/com/intellij/psi/codeStyle/MinusculeMatcher.java

@@ -190,22 +190,13 @@ public class MinusculeMatcher implements Matcher {
     Iterable<TextRange> fragments = matchingFragments(name);
     if (fragments != null) {
       Iterator<TextRange> iterator = fragments.iterator();
-      if (!iterator.hasNext() || isStartMatch(name, iterator.next().getStartOffset())) {
+      if (!iterator.hasNext() || iterator.next().getStartOffset() == 0) {
         return true;
       }
     }
     return false;
   }
 
-  private static boolean isStartMatch(@NotNull String name, int startIndex) {
-    for (int i = 0; i < startIndex; i++) {
-      if (!isWordSeparator(name.charAt(i))) {
-        return false;
-      }
-    }
-    return true;
-  }
-
   @Override
   public boolean matches(@NotNull String name) {
     // optimisation: name too short for this pattern