As observed in Kate 16.04.1 on Manjaro 64-bit and in 3.14.13 on Ubuntu 32-bit.  The behavior is slightly different with respect to the incorrect number of finds (see below), but it's always wrong and changes in both.


Reproducible: Always

Steps to Reproduce:
1. Make and open a file consisting of 64 newline characters (65 lines), e.g.:
$ printf '\n%.0s' {1..64} > kate-bug-test.txt
$ kate kate-bug-test.txt

2. Press Ctrl-R
Find: \n
Replace: ====\n
Mode: Escape Sequences
click Replace All

3. Close search, press Ctrl-Z to undo.

4. Repeat steps 2-3 several times.


Actual Results:  
YMMV.  For me:

On the newer version:
- cursor position doesn't seem to matter
- 1st time it finds 32 (all the odd-numbered).
- 2nd time it finds 1 (line 64).
- 3rd and following it finds 0.

On the older version:
- 1st time finds 32 (odd lines 1-63)
- 2nd time finds 32 (line 1, even lines 4-64)
- 3rd time finds 31 (line 1, odd lines 5-63)
- 4th time finds 31 (line 1, even lines 6-64)
- 5th time finds 30 (line 1, odd lines 7-63)
- 6th time finds 30 (line 1, even lines 8-64)
etc.


Expected Results:  
Should find and replace '\n' with '====\n' 64 times.