On 12/9/2019 1:10 PM, René Scharfe wrote: > Am 09.12.19 um 18:44 schrieb Derrick Stolee: >> On 12/9/2019 12:19 PM, Eric Sunshine wrote: >>> On Mon, Dec 9, 2019 at 12:11 PM René Scharfe <l.s.r@xxxxxx> wrote: >>>> Am 09.12.19 um 16:36 schrieb Derrick Stolee: >>>>> René Scharfe 0bb313a5 xdiff: unignore changes in function context >>>>> xdiff/xemit.c >>>>> 0bb313a5 223) xchp->i1 + xchp->chg1 <= s1 && >>>>> 0bb313a5 224) xchp->i2 + xchp->chg2 <= s2) >>>>> 0bb313a5 225) xchp = xchp->next; >>>> >>>> Hmm, line 223 *is* exercised by t4015.85. >>> >>> This, along with Dscho's[1] review of an earlier coverage report, >>> makes one wonder if there is some off-by-one error in the reporting >>> logic, such that it is reporting the wrong lines as not covered. >> >> This is definitely possible. I'll see if I can locate the bug in >> my report-generation code. >> >> However, line 222 is here [1] >> >> while (xchp != xch && >> >> So if this is always false, then the rest of the while condition >> will not be tested, nor will the body (line 225: xchp = xchp->next;). > > 0bb313a5 also added lines 228 and 229, which are not in the report, so > xchp != xch must be true at least once (it is, in t4015.85). > > 222) while (xchp != xch && > 223) xchp->i1 + xchp->chg1 <= s1 && > 224) xchp->i2 + xchp->chg2 <= s2) > 225) xchp = xchp->next; > 226) > 227) /* If so, show it after all. */ > 228) if (xchp != xch) { > 229) xch = xchp; Thanks for pointing out that context. My guess is that gcov is marking the line as uncovered because the && operator is on that line. I'm testing [1] by breaking style conventions and using the following: while (xchp != xch && xchp->i1 + xchp->chg1 <= s1 && xchp->i2 + xchp->chg2 <= s2) xchp = xchp->next; [1] https://dev.azure.com/git/git/_build/results?buildId=1453