Is there a diff tool (patch) that is aware of indentation?

Question

I'm regularly using the gnu-utils patch and diff. Using git, I often do:

git diff 

Often simple changes create a large patch because the only that changed was, for example, adding a if/else loop and everything inside is indented to the right.

Reviewing such a patch can be cumbersome because only line by line manual comparison can indicate if anything has essentially changed within the indented code. We may be speaking about a few lines of code only, or about dozens (or much more) of nested code. (I know: such an hypothetically large function would better be split into smaller functions, but that's beside the point).

Can't GNU diff/patch be aware when the only change within a code block is the indentation and let the developer know as much?

Are there any other diff tools that operate this way?

Edit: Ok, there is --ignore-space-change but then we are in a either/or situation: either we have a human-more-readable patch or we have a complete patch that the machine would know how to read. Can't we have the best of both world with a more elaborate diff tool that would show to the human space changes for what they are while allowing the machine to apply the patch fully?

Answer 1

With GNU diff you can pass -b or --ignore-space-change to ignore changes in the amount of white space in a patch.

If you use emacs and have been sent a patch, you can also use M-x diff-ignore-whitespace-hunk to reformat the patch to ignore white space in a particular hunk. Or diff-refine-hunk to highlight changes at a character by character level, which tends to point out the "meat" of a change.

As for applying patches, you can use the -l or --ignore-whitespace with GNU patch to ignore tabs and spaces changes. Just be careful with Python code :-)