expand "\r" treatment on to the previous lines in document to fix IDEA-170961 sys.stdout is severly damaged and does not execute '\r' correctly

platform/lang-impl/src/com/intellij/execution/impl/ConsoleViewImpl.java

@@ -685,7 +685,7 @@ public class ConsoleViewImpl extends JPanel implements ConsoleView, ObservableCo
         int startIndex = startsWithCR ? 1 : 0;
         for (int i = startIndex; i < deferredTokens.size(); i++) {
           TokenBuffer.TokenInfo deferredToken = deferredTokens.get(i);
-          addedText.append(deferredToken.getText());
+          addedText.append(deferredToken.getText()); // can just append texts because \r inside these tokens were already taken care of
         }
         if (startsWithCR) {
           // remove last line if any

platform/lang-impl/src/com/intellij/execution/impl/TokenBuffer.java

@@ -65,13 +65,8 @@ class TokenBuffer {
         TokenInfo tokenInfo = new TokenInfo(contentType, text.substring(start, crIndex), info);
         tokens.addLast(tokenInfo);
         size += tokenInfo.length();
-        removeLastLine();
-      }
-      else if (size == 0) {
-        // \r at the very beginning. return CR_TOKEN to signal this
-        tokens.addLast(CR_TOKEN);
-        size ++;
       }
+      removeLastLine();
       // text[start..crIndex) should be removed
       start = crIndex + 1;
     }
@@ -110,10 +105,16 @@ class TokenBuffer {
         TokenInfo newToken = new TokenInfo(last.contentType, text.substring(0, lfIndex + 1), last.getHyperlinkInfo());
         tokens.addLast(newToken);
         size -= text.length() - newToken.length();
-        break;
+        return;
       }
+      // remove the token entirely, move to the previous
       size -= text.length();
     }
+    if (tokens.isEmpty()) {
+      // \r at the very beginning. return CR_TOKEN to signal this
+      tokens.addLast(CR_TOKEN);
+      size ++;
+    }
   }
 
   private void trim() {

platform/platform-tests/testSrc/com/intellij/execution/impl/ConsoleViewImplTest.java

@@ -374,4 +374,14 @@ public class ConsoleViewImplTest extends LightPlatformTestCase {
                                                   () -> EditorTestUtil.executeAction(editor, true, handler),
                                                   "", null, editor.getDocument());
   }
+
+  public void testCRPrintCR() throws Exception {
+    for (int i=0;i<25;i++) {
+      myConsole.print("\r"+i, ConsoleViewContentType.NORMAL_OUTPUT);
+      Thread.sleep(100);
+    }
+    myConsole.flushDeferredText();
+    myConsole.waitAllRequests();
+    assertEquals("24", myConsole.getText());
+  }
 }