grep: fix --column --only-match for 2nd and later matches

"git grep --column --only-match" shows the 1-based column number of the first match on each line, but confusing numbers for further matches. Example: $ echo 123456789012345678901234567890 >file $ for d in 1 2 3 4 5 6 7 8 9 0 do git grep --no-index --column --only-matching $d file | awk -v FS=: -v l=$d: '{l = l sprintf("%3s", $2)} END {print l}' done 1: 1 2 12 2: 2 4 14 3: 3 6 16 4: 4 8 18 5: 5 10 20 6: 6 12 22 7: 7 14 24 8: 8 16 26 9: 9 18 28 0: 10 20 30 Report the column number of each match instead: $ for d in 1 2 3 4 5 6 7 8 9 0 do ./git grep --no-index --column --only-matching $d file | awk -v FS=: -v l=$d: '{l = l sprintf("%3s", $2)} END {print l}' done 1: 1 11 21 2: 2 12 22 3: 3 13 23 4: 4 14 24 5: 5 15 25 6: 6 16 26 7: 7 17 27 8: 8 18 28 9: 9 19 29 0: 10 20 30 We need to adjust the test in t7810 as well. The file it uses has the following five lines; I add a line highlighting the matches and a ruler at the bottom here, to make it easier to see that the second "mmap" indeed starts at column 14: foo mmap bar foo_mmap bar foo_mmap bar mmap foo mmap bar_mmap foo_mmap bar mmap baz ==== ==== 123456789 123456789 1 Reported-by: Brandon Chinn <brandonchinn178@gmail.com> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>