update CharArrayUtil.fromSequence doc, use it instead of fromSequenceStrict

platform/core-impl/src/com/intellij/openapi/editor/impl/CharArray.java

@@ -19,7 +19,6 @@ import com.intellij.diagnostic.Dumpable;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.editor.event.DocumentEvent;
 import com.intellij.openapi.util.text.StringUtil;
-import com.intellij.util.ArrayUtil;
 import com.intellij.util.LocalTimeCounter;
 import com.intellij.util.text.CharArrayCharSequence;
 import com.intellij.util.text.CharArrayUtil;
@@ -468,7 +467,7 @@ abstract class CharArray implements CharSequenceBackedByArray, Dumpable {
       try {
         flushDeferredChanged();
         if (myOriginalSequence != null && myArray == null) {
-          myArray = array = ArrayUtil.realloc(CharArrayUtil.fromSequence(myOriginalSequence), myOriginalSequence.length());
+          myArray = array = CharArrayUtil.fromSequence(myOriginalSequence);
           myStringRef = null;
         }
       }

platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java

@@ -617,7 +617,7 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
   @Override
   @NotNull
   public char[] textToCharArray() {
-    return CharArrayUtil.fromSequenceStrict(getViewProvider().getContents());
+    return CharArrayUtil.fromSequence(getViewProvider().getContents());
   }
 
   @NotNull

platform/lang-impl/src/com/intellij/psi/impl/source/LightPsiFileImpl.java

@@ -258,7 +258,7 @@ public abstract class LightPsiFileImpl extends PsiElementBase implements PsiFile
   @Override
   @NotNull
   public char[] textToCharArray() {
-    return CharArrayUtil.fromSequenceStrict(getViewProvider().getContents());
+    return CharArrayUtil.fromSequence(getViewProvider().getContents());
   }
 
   @Override

platform/util/src/com/intellij/util/text/CharArrayUtil.java

@@ -99,13 +99,12 @@ public class CharArrayUtil {
     }
   }
 
+  /**
+   * @deprecated use {@link #fromSequence(CharSequence)}
+   */
   @NotNull
   public static char[] fromSequenceStrict(@NotNull CharSequence seq) {
-    char[] chars = fromSequence(seq);
-    if (seq.length() == chars.length) return chars;
-    char[] strictChars = new char[seq.length()];
-    System.arraycopy(chars, 0, strictChars, 0, seq.length());
-    return strictChars;
+    return fromSequence(seq);
   }
 
   @Nullable
@@ -126,7 +125,6 @@ public class CharArrayUtil {
 
   /**
    * @return the underlying char[] array if any, or the new chara array if not
-   * NOTE RETURNED ARRAY LENGTH MAY HAVE BE DIFFERENT FROM THE seq.length()
    */
   @NotNull
   public static char[] fromSequence(@NotNull CharSequence seq) {
@@ -155,6 +153,11 @@ public class CharArrayUtil {
       ((StringBuffer)seq).getChars(0, seq.length(), chars, 0);
       return chars;
     }
+    if (seq instanceof StringBuilder) {
+      char[] chars = new char[seq.length()];
+      ((StringBuilder)seq).getChars(0, seq.length(), chars, 0);
+      return chars;
+    }
 
     if (seq instanceof String) {
       char[] chars = new char[seq.length()];