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>

diff --git a/builtin/blame.c b/builtin/blame.c
index 079dcd3407881ce0ea988c3f487faf8ca6d3e5d2..e70b089a67d4c4b87663faebd788c437c1f1ce73 100644 (file)
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -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;

diff --git a/t/annotate-tests.sh b/t/annotate-tests.sh
index 22db31e580600aaa951e5b2e3278d2fff3b99aed..015acabf30f6fdf11dc6d6a7f2b40f8487f27db6 100644 (file)
--- a/t/annotate-tests.sh
+++ b/t/annotate-tests.sh
@@ -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
 '