blame: fix -L bounds checking bug

Since inception, -LX,Y has correctly reported an out-of-range error when
Y is beyond end of file, however, X was not checked, and an out-of-range
X would cause a crash.  92f9e273 (blame: prevent a segv when -L given
start > EOF; 2010-02-08) attempted to rectify this shortcoming but has
its own off-by-one error which allows X to extend one line past end of
file.  For example, given a file with 5 lines:

  git blame -L5 foo  # OK, blames line 5
  git blame -L6 foo  # accepted, no error, no output, huh?
  git blame -L7 foo  # error "fatal: file foo has only 5 lines"

Fix this bug.

In order to avoid regressing "blame foo" when foo is an empty file, the
fix is slightly more complicated than changing '<' to '<='.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Eric Sunshine 2013-07-31 04:15:38 -04:00 committed by Junio C Hamano
parent a8fa8eca3f
commit 164a9cf430
2 changed files with 6 additions and 6 deletions

View File

@ -2495,13 +2495,13 @@ parse_done:
bottom = top = 0;
if (bottomtop)
prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
if (lno < top || ((lno || bottom) && lno < bottom))
die("file %s has only %lu lines", path, lno);
if (bottom < 1)
bottom = 1;
if (top < 1)
top = lno;
bottom--;
if (lno < top || lno < bottom)
die("file %s has only %lu lines", path, lno);
ent = xcalloc(1, sizeof(*ent));
ent->lno = bottom;

View File

@ -232,7 +232,7 @@ test_expect_success 'blame -L X (X == nlines)' '
check_count -L$n C 1
'
test_expect_failure 'blame -L X (X == nlines + 1)' '
test_expect_success 'blame -L X (X == nlines + 1)' '
n=$(expr $(wc -l <file) + 2) &&
test_must_fail $PROG -L$n file
'
@ -321,7 +321,7 @@ test_expect_success 'blame -L 0 empty (undocumented)' '
check_count -h HEAD^^ -f incremental -L0
'
test_expect_failure 'blame -L 1 empty' '
test_expect_success 'blame -L 1 empty' '
test_must_fail $PROG -L1 incremental HEAD^^
'
@ -341,7 +341,7 @@ test_expect_success 'blame -L 1 half' '
check_count -h HEAD^ -f incremental -L1 I 1
'
test_expect_failure 'blame -L 2 half' '
test_expect_success 'blame -L 2 half' '
test_must_fail $PROG -L2 incremental HEAD^
'
@ -361,7 +361,7 @@ test_expect_success 'blame -L 1 full' '
check_count -f incremental -L1 I 1
'
test_expect_failure 'blame -L 2 full' '
test_expect_success 'blame -L 2 full' '
test_must_fail $PROG -L2 incremental
'