HTML file input control with capture and accept attributes works wrong?

This is the actual answer. Just post it here for next users:

Actually, it seems that current implementations don’t rely on the capture attribute at all, but only on the type and accept attributes: the browser displays a dialog box in which the user can choose where the file has to be taken, and the capture attribute is not taken into consideration. For example, iOS Safari relies on the accept attribute (not capture) for images and videos (not audio). Even if you don't use the accept attribute, the browser will let you choose between "Take Photo or Video" and "Choose Existing" (thanks to@firt for pointing this out).

From this

EDITED 17 Feb 2016: This behavior is still active on devices.

The "correct" code and the one you should be using is the 5th one:

<input type="file" accept="image/*">

Which is why it's working correctly on most of your devices. The above code is correct, complete and enough to tell both iOS and Android that:

1. you want to capture an image (use accept="video/*" for video and accept="audio/*" for audio, skip altogether to allow anything).
2. the user should be able to select an existing one OR capture it on the spot

2. Can I trust for browsers what its will always add camera to upload dialog without capture attribute?

Yes.

The capture attribute is NOT used to include the camera option in the dialog (<input type="file"> is enough for that) but to indicate that direct capture from the webcam is preferred. From the W3C Recommendation spec:

The capture attribute is a boolean attribute that, if specified, indicates that the capture of media directly from the device...is preferred.

capture is supported by Android 3.0+ which will take you straight to the camera app if capture is present in the code.

There's no support in iOS6-10 who will always give you at least 2 options: "Take Photo" + "Photo Library".

The capture attribute has evolved in the spec (which is why you'll see several versions throughout StackOverflow):

1. July 2010: accept="image/*;capture=camera"
2. Apr 2011 : capture="camera" (String)
3. Dec 2012: capture (Boolean, W3C Candidate Recommendation,)

PS: I've done a ton of research on HTML Media Capture, see Correct Syntax for HTML Media Capture and The New Prompt for Media Capture in iOS9. Here's my test bench with 20+ code combinations.

For others to reference this is the behavior of Chrome on Android 9 as of today (Feb 2020):

  Must be selected from album
  <input type="file" accept="image/*">
 
  Must be captured from camera
  <input type="file" accept="image/*" capture="">
 
  Allowed user to choose either from album or camera
  <input type="file" accept="image/*;capture=camera">