Fixing Issue facebook#21243 - capitalized I's when emojiis are presen…

…t after the text being edited.

Libraries/Text/TextInput/RCTBaseTextInputView.m

@@ -98,10 +98,40 @@ - (NSAttributedString *)attributedText
   return self.backedTextInputView.attributedText;
 }
 
+- (BOOL)textOf:(NSAttributedString*)newText equals:(NSAttributedString*)oldText{
+  // When the dictation is running we can't update the attibuted text on the backed up text view
+  // because setting the attributed string will kill the dictation. This means that we can't impose
+  // the settings on a dictation.
+  // Similarly, when the user is in the middle of inputting some text in Japanese/Chinese, there will be styling on the
+  // text that we should disregard. See https://developer.apple.com/documentation/uikit/uitextinput/1614489-markedtextrange?language=objc
+  // for more info.
+  // Also if user has added an emoji, the sytem adds a font attribute for the emoji and stores the original font in NSOriginalFont.
+  // Lastly, when entering a password, etc., there will be additional styling on the field as the native text view
+  // handles showing the last character for a split second.
+  __block BOOL fontHasBeenUpdatedBySystem = false;
+  [oldText enumerateAttribute:@"NSOriginalFont" inRange:NSMakeRange(0, oldText.length) options:0 usingBlock:^(id value, NSRange range, BOOL *stop) {
+    if (value){
+      fontHasBeenUpdatedBySystem = true;
+    }
+  }];
+
+  BOOL shouldFallbackToBareTextComparison =
+  [self.backedTextInputView.textInputMode.primaryLanguage isEqualToString:@"dictation"] ||
+  self.backedTextInputView.markedTextRange ||
+  self.backedTextInputView.isSecureTextEntry ||
+  fontHasBeenUpdatedBySystem;
+
+  if (shouldFallbackToBareTextComparison) {
+    return ([newText.string isEqualToString:oldText.string]);
+  } else {
+    return ([newText isEqualToAttributedString:oldText]);
+  }
+}
+
 - (void)setAttributedText:(NSAttributedString *)attributedText
 {
   NSInteger eventLag = _nativeEventCount - _mostRecentEventCount;
-
+  BOOL textNeedsUpdate = NO;
   // Remove tag attribute to ensure correct attributed string comparison.
   NSMutableAttributedString *const backedTextInputViewTextCopy = [self.backedTextInputView.attributedText mutableCopy];
   NSMutableAttributedString *const attributedTextCopy = [attributedText mutableCopy];
@@ -112,7 +142,9 @@ - (void)setAttributedText:(NSAttributedString *)attributedText
   [attributedTextCopy removeAttribute:RCTTextAttributesTagAttributeName
                                 range:NSMakeRange(0, attributedTextCopy.length)];
 
-  if (eventLag == 0 && ![attributedTextCopy isEqualToAttributedString:backedTextInputViewTextCopy]) {
+  textNeedsUpdate = ([self textOf:attributedTextCopy equals:backedTextInputViewTextCopy] == NO);
+
+  if (eventLag == 0 && textNeedsUpdate) {
     UITextRange *selection = self.backedTextInputView.selectedTextRange;
     NSInteger oldTextLength = self.backedTextInputView.attributedText.string.length;