Merge branch 'tg/range-diff-corner-case-fix'

Recently added "range-diff" had a corner-case bug to cause it
segfault, which has been corrected.

* tg/range-diff-corner-case-fix:
linear-assignment: fix potential out of bounds memory access

diff --cc t/t3206-range-diff.sh
index d481f2925924317a44f1bba65e6ca41fc57cc65d,fb4c13a84ade63470f4dabc976ff5f5369c17e1e..045aca1c18bec3d5278eb50a461df0588dd84618
--- 1/t/t3206-range-diff.sh
--- 2/t/t3206-range-diff.sh
+++ b/t/t3206-range-diff.sh
@@@ -122,6 -122,6 +122,11 @@@ test_expect_success 'changed commit' 
        test_cmp expected actual
  '
  
++test_expect_success 'no commits on one side' '
++      git commit --amend -m "new message" &&
++      git range-diff master HEAD@{1} HEAD
++'
++
  test_expect_success 'changed message' '
        git range-diff --no-color topic...changed-message >actual &&
        sed s/Z/\ /g >expected <<-EOF &&