one-letter prefix is not a subject for middle-word matching

java/java-tests/testSrc/com/intellij/codeInsight/completion/CompletionStyleTest.java

@@ -110,7 +110,6 @@ public class CompletionStyleTest extends LightCodeInsightTestCase{
 
     configureByFile(path + "/before3.java");
     performSmartCompletion();
-    select(Lookup.NORMAL_SELECT_CHAR, 0);
     checkResultByFile(path + "/after3.java");
   }
 

java/java-tests/testSrc/com/intellij/codeInsight/completion/JavaAutoPopupTest.groovy

@@ -558,11 +558,15 @@ public interface Test {
 
     edt { myFixture.performEditorAction(IdeActions.ACTION_EDITOR_MOVE_CARET_RIGHT) }
     assert myFixture.editor.caretModel.offset == offset + 1
+    joinAutopopup()
+    joinCompletion()
     assertContains "iterable"
     assertEquals 'iterable', lookup.currentItem.lookupString
 
     edt { myFixture.performEditorAction(IdeActions.ACTION_EDITOR_MOVE_CARET_LEFT) }
     assert myFixture.editor.caretModel.offset == offset
+    joinAutopopup()
+    joinCompletion()
     assertContains "if", "iterable", "int"
     assertEquals 'iterable', lookup.currentItem.lookupString
 
@@ -773,7 +777,7 @@ class Foo {
   public void testRestartWithVisibleLookup() {
     registerContributor(LongContributor, LoadingOrder.FIRST)
 
-    myFixture.configureByText("a.java", """ class Foo { { int abcdef; a<caret> } } """)
+    myFixture.configureByText("a.java", """ class Foo { { int abcdef, abcdefg; ab<caret> } } """)
     myFixture.completeBasic()
     while (!lookup.shown) {
       Thread.sleep(1)
@@ -781,10 +785,10 @@ class Foo {
     def l = lookup
     edt {
       assert lookup.calculating
-      myFixture.type 'b'
+      myFixture.type 'c'
     }
     joinCommit {
-      myFixture.type 'c'
+      myFixture.type 'd'
     }
     joinAutopopup()
     joinCompletion()

java/java-tests/testSrc/com/intellij/codeInsight/completion/JavadocCompletionTest.java

@@ -54,7 +54,7 @@ public class JavadocCompletionTest extends LightFixtureCompletionTestCase {
 
   public void testNamesInMethod1() throws Exception {
     configureByFile("MethodTagName1.java");
-    assertStringItems("see", "serialData", "since", "class", "throws");
+    assertStringItems("see", "serialData", "since");
   }
 
   public void testParamValueCompletion() throws Exception {

java/java-tests/testSrc/com/intellij/codeInsight/completion/KeywordCompletionTest.java

@@ -85,9 +85,9 @@ public class KeywordCompletionTest extends LightCompletionTestCase {
   public void testNullInIf() throws Exception { doTest(true); }
   public void testNullInReturn() throws Exception { doTest(true); }
   public void testExtendsInMethodParameters() throws Exception { doTest(false); }
-  public void testInstanceOf1() throws Exception { doTest(true); }
+  public void testInstanceOf1() throws Exception { doTest(false); }
   public void testInstanceOf2() throws Exception { doTest(false); }
-  public void testInstanceOf3() throws Exception { doTest(true); }
+  public void testInstanceOf3() throws Exception { doTest(false); }
   public void testCatchFinally() throws Exception { doTest(2, "catch", "finally"); }
   public void testSuper1() throws Exception { doTest(1, "super"); }
   public void testSuper2() throws Exception { doTest(0, "super"); }

java/java-tests/testSrc/com/intellij/codeInsight/completion/VariablesCompletionTest.groovy

@@ -137,7 +137,7 @@ public class VariablesCompletionTest extends LightFixtureCompletionTestCase {
   }
 
   public void testFieldOutOfAnonymous() throws Exception {
-    doSelectTest("TestFieldOutOfAnonymous.java", "TestFieldOutOfAnonymousResult.java");
+    doTest("TestFieldOutOfAnonymous.java", "TestFieldOutOfAnonymousResult.java");
   }
 
   public void testUnresolvedMethodName() throws Exception {

platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/BackspaceHandler.java

@@ -56,6 +56,10 @@ public class BackspaceHandler extends EditorActionHandler {
       return;
     }
 
+    if (process != null) {
+      process.prefixUpdated();
+    }
+
     if (hideOffset < editor.getCaretModel().getOffset()) {
       if (process != null) {
         process.scheduleRestart();

platform/platform-tests/testSrc/com/intellij/psi/util/NameUtilTest.java

@@ -214,6 +214,15 @@ public class NameUtilTest extends UsefulTestCase {
     assertMatches("text*:sh", "textField:shouldChangeCharactersInRange:replacementString:");
   }
 
+  public void testMiddleMatchingMinimumTwoConsecutiveLettersInWordMiddle() {
+    assertMatches("*fo", "reformat");
+    assertMatches("*f", "reFormat");
+    assertMatches("*f", "format");
+    assertMatches("*f", "Format");
+    assertMatches("*Stri", "string");
+    assertDoesntMatch("*f", "reformat");
+  }
+
   public void testMiddleMatching() {
     assertTrue(caseInsensitiveMatcher("*old").matches("folder"));
     assertMatches("SWU*H*7", "SWUpgradeHdlrFSPR7Test");
@@ -395,9 +404,9 @@ public class NameUtilTest extends UsefulTestCase {
   public void testPreferStartMatchToMiddleMatch() {
     assertPreference(" fb", "FooBar", "_fooBar", NameUtil.MatchingCaseSensitivity.NONE);
     assertPreference("*foo", "barFoo", "foobar");
-    assertPreference("*f", "barfoo", "barFoo");
-    assertPreference("*f", "barfoo", "foo");
-    assertPreference("*f", "asdf", "Foo", NameUtil.MatchingCaseSensitivity.NONE);
+    assertPreference("*fo", "barfoo", "barFoo");
+    assertPreference("*fo", "barfoo", "foo");
+    assertPreference("*fo", "asdfo", "Foo", NameUtil.MatchingCaseSensitivity.NONE);
     assertPreference(" sto", "ArrayStoreException", "StackOverflowError", NameUtil.MatchingCaseSensitivity.NONE);
     assertPreference(" EUC-", "x-EUC-TW", "EUC-JP");
     assertPreference(" boo", "Boolean", "boolean", NameUtil.MatchingCaseSensitivity.NONE);
@@ -450,10 +459,10 @@ public class NameUtilTest extends UsefulTestCase {
       public void run() {
         for (int i = 0; i < 100000; i++) {
           for (MinusculeMatcher matcher : matching) {
-            assertTrue(matcher.matches(longName));
+            assertTrue(matcher.toString(), matcher.matches(longName));
           }
           for (MinusculeMatcher matcher : nonMatching) {
-            assertFalse(matcher.matches(longName));
+            assertFalse(matcher.toString(), matcher.matches(longName));
           }
         }
       }

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

@@ -177,6 +177,7 @@ public class MinusculeMatcher implements Matcher {
 
   @Nullable
   private FList<TextRange> skipChars(String name, int patternIndex, int nameIndex, boolean maySkipNextChar) {
+    boolean veryStart = patternIndex == 0;
     while ('*' == myPattern[patternIndex]) {
       patternIndex++;
       if (patternIndex == myPattern.length) {
@@ -201,6 +202,17 @@ public class MinusculeMatcher implements Matcher {
         continue;
       }
 
+      if (veryStart && next > 0 && !NameUtil.isWordStart(name, next)) {
+        if (next == name.length() - 1) {
+          return null;
+        }
+        if (patternIndex == myPattern.length - 1 ||
+            myPattern[patternIndex + 1] != name.charAt(next + 1) && Character.isLetter(myPattern[patternIndex + 1])) {
+          fromIndex = next + 1;
+          continue;
+        }
+      }
+
       FList<TextRange> ranges = matchName(name, patternIndex, next);
       if (ranges != null) {
         return ranges;
@@ -324,4 +336,12 @@ public class MinusculeMatcher implements Matcher {
 
     return matchName(name, 0, 0);
   }
+
+  @Override
+  public String toString() {
+    return "MinusculeMatcher{" +
+           "myPattern=" + new String(myPattern) +
+           ", myOptions=" + myOptions +
+           '}';
+  }
 }