WinMerge - Is there a way to line up shifted/moved code blocks?

Question

When using WinMerge I am looking at a file that has had a block of code inserted into a function which causes the rest of the file to be out of sync in the comparison. Mine is much more complex but essentially the same as the simple example below:

  FILE 1                   FILE 2
1 int main() {             int main() {
2
3   int a = 3;               int a = 3;
4   a += 5;                  for(int i = 0; i < a; ++a)
5 }                             a += i;
6                           
7                            a += 5;
8                         }

WinMerge instead of recognizing the for-loop as an inserted block and showing the rest of the file the same it would show differences on line 4,5,6,7,8. I would expect it to sync line 4 of file 1 to line 7 of file 2 and make it a much cleaner diff. Is there a setting for this? I have played with the "Moved Code Block" setting but it simply highlights the matching code block later in the file instead of lining them up.

Any suggestions?

Sublingual

After doing some research it does not appear to be possible. :( – Sublingual

still not possible, or possible with any other tool? – Banquette

Beyond Compare is a great diff tool that allows this. Unfortunately, it isn't free – Golliner

Answer 1

Try this instead:

• Select the line on the left file of the merge to match up.
• Do the same on the right.
• You now have 2 lines selected concurrently.
• Menu merge -> Add Synchronization Point (Alt + S)

This will line up those lines on both files.

Quijano

Thanks! The same result is possible in Beyond Compare with F7 but my client doesn't want to spring for a closed-source merge tool, so I'm learning and teaching them WinMerge. – Aquileia

Answer 2

I know what you mean, but your example worked for me.

I have the problem when the compare syncs up on say, blank lines.

I'm looking into the line filter...

Virginiavirginie

Thanks, for the follow up. The example I listed is pretty simplistic and it may actually work. But on a large file with many changes along with larger blocks of code changes like the one I listed it essentially calls the whole file different making the tool useless. – Sublingual

A minimal working example would be useful here. Some of these diff issues come down to subtle changes like carriage returns, length of the line, etc. – Superficies