Thumbnail frame_index issue

[mmchavda]

Describe the bug
While migrating old paperclip 5.0 to new 7.0, execution throw error like

convert: unable to open image `/tmp/4d22f0c8f6b3e60d52c9633d4ad6b6e920211004-4396-hdequv.jpg[]': No such file or directory @ error/blob.c/OpenBlob/2712.
convert: no decode delegate for this image format `JPG[]' @ error/constitute.c/ReadImage/501.
convert: no images defined `/tmp/f5538c43af586218e55e52c89a854e5320211004-4396-ticqse.jpg' @ error/convert.c/ConvertImageCommand/3210.

Issue with, /tmp/ image should include [] frame_index blank at last.

Issue is with "def make" with below syntax
frame = animated? ? "" : "[#{@frame_index}]"
I have updated it with
frame = animated? ? "" : (@frame_index.present? "[#{@frame_index}]" : "")

I don't know if it's issue due to existing code or need to fix in paperclip.
Request you to fix the issue if it's bug in paperclip gems or provide valid approach to solve the issue.

[ssinghi]

@mmchavda can you please provide a link to a sample image throwing this error. It will make it much easier to debug and fix this.

[ssinghi]

@mmchavda were you able to fix the issue?