From ab60c693a2f473c9952ad8ce31e94df5f76431b9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Mon, 18 Aug 2025 13:13:09 +0200 Subject: [PATCH 1/2] line-log: fix assertion error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When line-level log is invoked with more than one disjoint line range in the same file, and one of the commits happens to change that file such that: - the last line of a line range R(n) immediately preceeds the first line modified or added by a hunk H, and - subtracting the number of lines added by hunk H from the start and end of the subsequent line range R(n+1) would result in a range overlapping with line range R(n), then git aborts with an assertion error, because those overlapping line ranges violate the invariants: $ git log --oneline -p 73e4e2f (HEAD -> master) Add lines 6 7 8 9 10 diff --git a/file b/file index 572d5d9..00935f1 100644 --- a/file +++ b/file @@ -3,3 +3,8 @@ Line 2 Line 3 Line 4 Line 5 +Line 6 +Line 7 +Line 8 +Line 9 +Line 10 66e3561 Add lines 1 2 3 4 5 diff --git a/file b/file new file mode 100644 index 0000000..572d5d9 --- /dev/null +++ b/file @@ -0,0 +1,5 @@ +Line 1 +Line 2 +Line 3 +Line 4 +Line 5 $ git log --oneline -L3,5:file -L7,8:file git: line-log.c:73: range_set_append: Assertion `rs->nr == 0 || rs->ranges[rs->nr-1].end <= a' failed. Aborted (core dumped) The line-log machinery encodes line and diff ranges internally as [start, end) pairs, i.e. include 'start' but exclude 'end', and line numbering starts at 0 (as opposed to the -LX,Y option, where it starts at 1, IOW the parameter -L3,5 is represented internally as { start = 2, end = 5 }). The reason for this assertion error and some related issues is that there are a couple of places where 'end' is mistakenly considered to be part of the range: - When a commit modifies an interesting path, the line-log machinery first checks which diff range (i.e. hunk) modify any line ranges. This is done in diff_ranges_filter_touched(), where the outer loop iterates over the diff ranges, and in each iteration the inner loop advances the line ranges supposedly until the current line range ends at or after the current diff range starts, and then the current diff and line ranges are checked for overlap. For HEAD in the above example the first line range [2, 5) ends just before the diff range [5, 10) starts, so the inner loop should advance, and then the second line range [6, 8) and the diff range should be checked for overlap. Unfortunately, the condition of the inner loop mistakenly considers 'end' as part of the line range, and, seeing the diff range starting at 5 and the line range ending at 5, it doesn't skip the first range. Consequently, the diff range and the first line range are checked for overlap, and after that the outer loop runs out of diff ranges, and then the processing goes on in the false belief that this commit didn't touch any of the interesting line ranges. The line-log machinery later shifts the line ranges to account for any added/removed lines in the diff ranges preceeding each line range. This leaves the first line range intact, but attempts to shift the second line range [6, 8) by 5 lines towards the beginning of the file, resulting in [1, 3), triggering the assertion error, because the two overlapping line ranges violate the invariants. Fix that loop condition in diff_ranges_filter_touched() to not treat 'end' as part of the line range. - With the above fix the assertion error is gone... but, alas, we now get stuck in an endless loop! This happens in range_set_difference(), where a couple of nested loops iterate over the line and diff ranges, and a condition is supposed to break the middle loop when the current line range ends before the current diff range, so processing could continue with the next line range. For HEAD in the above example the first line range [2, 5) ends just before the diff range [5, 10) starts, so this condition should trigger and break the middle loop. Unfortunately, just like in the case of the assertion error, this conditions mistakenly considers 'end' as part of the line range, and, seeing the line range ending at 5 and the diff range starting at 5, it doesn't break the loop, which will then go on and on. Fix this condition in range_set_difference() to not treat 'end' as part of the line range. - With the above fix the endless loop is gone... but, alas, the output is now wrong, as it shows both line ranges for HEAD, even though the first line range is not modified by that commit: $ git log --oneline -L3,5:file -L7,8:file 73e4e2f (HEAD -> master) Add lines 6 7 8 9 10 diff --git a/file b/file --- a/file +++ b/file @@ -3,3 +3,3 @@ Line 3 Line 4 Line 5 @@ -6,0 +7,2 @@ +Line 7 +Line 8 66e3561 Add lines 1 2 3 4 5 diff --git a/file b/file --- /dev/null +++ b/file @@ -0,0 +3,3 @@ +Line 3 +Line 4 +Line 5 In dump_diff_hacky_one() a couple of nested loops are responsible for finding and printing the modified line ranges: the big outer loop iterates over all line ranges, and the first inner loop skips over the diff ranges that end before the start of the current line range. This is followed by a condition checking whether the current diff range starts after the end of the current line range, which, when fulfilled, continues and advances the outer loop to the next line range. For HEAD in the above example the first line range [2, 5) ends just before the diff range [5, 10), so this condition should trigger, and the outer loop should advance to the second line range. Unfortunately, just like in the previous cases, this condition mistakenly considers 'end' as part of the line range, and, seeing the first line range ending at 5 and the diff range starting at 5, it doesn't continue to advance the outher loop, but goes on to show the (unmodified) first line range. Fix this condition to not treat 'end' as part of the line range, just like in the previous cases. After all this the command in the above example finally finishes and produces the right output: $ git log --oneline -L3,5:file -L7,8:file 73e4e2f (HEAD -> master) Add lines 6 7 8 9 10 diff --git a/file b/file --- a/file +++ b/file @@ -6,0 +7,2 @@ +Line 7 +Line 8 66e3561 Add lines 1 2 3 4 5 diff --git a/file b/file --- /dev/null +++ b/file @@ -0,0 +3,3 @@ +Line 3 +Line 4 +Line 5 Add a canned test similar to the above example, with the line ranges adjusted to the test repository's history. Reported-by: Evgeni Chasnovski Signed-off-by: SZEDER Gábor Signed-off-by: Junio C Hamano --- line-log.c | 6 +- t/t4211-line-log.sh | 2 + t/t4211/sha1/expect.no-assertion-error | 90 ++++++++++++++++++++++++ t/t4211/sha256/expect.no-assertion-error | 90 ++++++++++++++++++++++++ 4 files changed, 185 insertions(+), 3 deletions(-) create mode 100644 t/t4211/sha1/expect.no-assertion-error create mode 100644 t/t4211/sha256/expect.no-assertion-error diff --git a/line-log.c b/line-log.c index 628e3fe3ae..9cb8ea1484 100644 --- a/line-log.c +++ b/line-log.c @@ -201,7 +201,7 @@ static void range_set_difference(struct range_set *out, * b: ------| */ j++; - if (j >= b->nr || end < b->ranges[j].start) { + if (j >= b->nr || end <= b->ranges[j].start) { /* * b exhausted, or * a: ----| @@ -408,7 +408,7 @@ static void diff_ranges_filter_touched(struct diff_ranges *out, assert(out->target.nr == 0); for (i = 0; i < diff->target.nr; i++) { - while (diff->target.ranges[i].start > rs->ranges[j].end) { + while (diff->target.ranges[i].start >= rs->ranges[j].end) { j++; if (j == rs->nr) return; @@ -941,7 +941,7 @@ static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *rang while (j < diff->target.nr && diff->target.ranges[j].end < t_start) j++; - if (j == diff->target.nr || diff->target.ranges[j].start > t_end) + if (j == diff->target.nr || diff->target.ranges[j].start >= t_end) continue; /* Scan ahead to determine the last diff that falls in this range */ diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh index 950451cf6a..0a7c3ca42f 100755 --- a/t/t4211-line-log.sh +++ b/t/t4211-line-log.sh @@ -78,6 +78,8 @@ canned_test "-L :main:a.c -L 4,18:a.c simple" multiple-overlapping canned_test "-L 4:a.c -L 8,12:a.c simple" multiple-superset canned_test "-L 8,12:a.c -L 4:a.c simple" multiple-superset +canned_test "-L 10,16:b.c -L 18,26:b.c main" no-assertion-error + test_bad_opts "-L" "switch.*requires a value" test_bad_opts "-L b.c" "argument not .start,end:file" test_bad_opts "-L 1:" "argument not .start,end:file" diff --git a/t/t4211/sha1/expect.no-assertion-error b/t/t4211/sha1/expect.no-assertion-error new file mode 100644 index 0000000000..994c37db1e --- /dev/null +++ b/t/t4211/sha1/expect.no-assertion-error @@ -0,0 +1,90 @@ +commit 0d8dcfc6b968e06a27d5215bad1fdde3de9d6235 +Author: Thomas Rast +Date: Thu Feb 28 10:50:24 2013 +0100 + + move within the file + +diff --git a/b.c b/b.c +--- a/b.c ++++ b/b.c +@@ -25,0 +18,9 @@ ++long f(long x) ++{ ++ int s = 0; ++ while (x) { ++ x /= 2; ++ s++; ++ } ++ return s; ++} + +commit 4659538844daa2849b1a9e7d6fadb96fcd26fc83 +Author: Thomas Rast +Date: Thu Feb 28 10:48:43 2013 +0100 + + change back to complete line + +diff --git a/a.c b/a.c +--- a/a.c ++++ b/a.c +@@ -18,5 +18,7 @@ + int main () + { + printf("%ld\n", f(15)); + return 0; +-} +\ No newline at end of file ++} ++ ++/* incomplete lines are bad! */ + +commit 100b61a6f2f720f812620a9d10afb3a960ccb73c +Author: Thomas Rast +Date: Thu Feb 28 10:48:10 2013 +0100 + + change to an incomplete line at end + +diff --git a/a.c b/a.c +--- a/a.c ++++ b/a.c +@@ -18,5 +18,5 @@ + int main () + { + printf("%ld\n", f(15)); + return 0; +-} ++} +\ No newline at end of file + +commit a6eb82647d5d67f893da442f8f9375fd89a3b1e2 +Author: Thomas Rast +Date: Thu Feb 28 10:45:16 2013 +0100 + + touch both functions + +diff --git a/a.c b/a.c +--- a/a.c ++++ b/a.c +@@ -17,5 +17,5 @@ + int main () + { +- printf("%d\n", f(15)); ++ printf("%ld\n", f(15)); + return 0; + } + +commit de4c48ae814792c02a49c4c3c0c757ae69c55f6a +Author: Thomas Rast +Date: Thu Feb 28 10:44:48 2013 +0100 + + initial + +diff --git a/a.c b/a.c +--- /dev/null ++++ b/a.c +@@ -0,0 +16,5 @@ ++int main () ++{ ++ printf("%d\n", f(15)); ++ return 0; ++} diff --git a/t/t4211/sha256/expect.no-assertion-error b/t/t4211/sha256/expect.no-assertion-error new file mode 100644 index 0000000000..36ed12aa9c --- /dev/null +++ b/t/t4211/sha256/expect.no-assertion-error @@ -0,0 +1,90 @@ +commit eb871b8aa9aff323e484723039c9a92ab0266e060bc0ef2afb08fadda25c5ace +Author: Thomas Rast +Date: Thu Feb 28 10:50:24 2013 +0100 + + move within the file + +diff --git a/b.c b/b.c +--- a/b.c ++++ b/b.c +@@ -25,0 +18,9 @@ ++long f(long x) ++{ ++ int s = 0; ++ while (x) { ++ x /= 2; ++ s++; ++ } ++ return s; ++} + +commit 5526ed05c2476b56af8b7be499e8f78bd50f490740733a9ca7e1f55878fa90a9 +Author: Thomas Rast +Date: Thu Feb 28 10:48:43 2013 +0100 + + change back to complete line + +diff --git a/a.c b/a.c +--- a/a.c ++++ b/a.c +@@ -18,5 +18,7 @@ + int main () + { + printf("%ld\n", f(15)); + return 0; +-} +\ No newline at end of file ++} ++ ++/* incomplete lines are bad! */ + +commit 29f32ac3141c48b22803e5c4127b719917b67d0f8ca8c5248bebfa2a19f7da10 +Author: Thomas Rast +Date: Thu Feb 28 10:48:10 2013 +0100 + + change to an incomplete line at end + +diff --git a/a.c b/a.c +--- a/a.c ++++ b/a.c +@@ -18,5 +18,5 @@ + int main () + { + printf("%ld\n", f(15)); + return 0; +-} ++} +\ No newline at end of file + +commit ccf97b9878189c40a981da50b15713bb80a35755326320ec80900caf22ced46f +Author: Thomas Rast +Date: Thu Feb 28 10:45:16 2013 +0100 + + touch both functions + +diff --git a/a.c b/a.c +--- a/a.c ++++ b/a.c +@@ -17,5 +17,5 @@ + int main () + { +- printf("%d\n", f(15)); ++ printf("%ld\n", f(15)); + return 0; + } + +commit 1dd7e9b2b1699324b53b341e728653b913bc192a14dfea168c5b51f2b3d03592 +Author: Thomas Rast +Date: Thu Feb 28 10:44:48 2013 +0100 + + initial + +diff --git a/a.c b/a.c +--- /dev/null ++++ b/a.c +@@ -0,0 +16,5 @@ ++int main () ++{ ++ printf("%d\n", f(15)); ++ return 0; ++} From e3106998ff84c9e1b548b72e0b034ca837d6c06b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Mon, 18 Aug 2025 13:13:10 +0200 Subject: [PATCH 2/2] line-log: show all line ranges touched by the same diff range MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When line-level log is invoked with more than one disjoint line range in the same file, and one of the commits happens to change that file such that one diff range modifies more than one line range, then changes to all modified line ranges should be shown, but only the changes in the first modified line range are: $ git log --oneline -p 80ca903 (HEAD -> master) Initial diff --git a/file b/file new file mode 100644 index 0000000..00935f1 --- /dev/null +++ b/file @@ -0,0 +1,10 @@ +Line 1 +Line 2 +Line 3 +Line 4 +Line 5 +Line 6 +Line 7 +Line 8 +Line 9 +Line 10 $ git log --oneline -L1,2:file -L4,5:file -L7,8:file 80ca903 (HEAD -> master) Initial diff --git a/file b/file --- /dev/null +++ b/file @@ -0,0 +1,2 @@ +Line 1 +Line 2 The line-log-specific diff printer is already clever enough to handle the case when one line range covers multiple diff ranges, but the possibility of one diff range touching multiple disjoint line ranges was apparently overlooked. Add the necessary condition to dump_diff_hacky_one() to handle this case as well, and show all modified line ranges: $ git log --oneline -L1,2:file -L4,5:file -L7,8:file 0f9a5b4 (HEAD -> master) Initial diff --git a/file b/file --- /dev/null +++ b/file @@ -0,0 +1,2 @@ +Line 1 +Line 2 @@ -0,0 +4,2 @@ +Line 4 +Line 5 @@ -0,0 +7,2 @@ +Line 7 +Line 8 This bug was already present in the initial line-log implementation added in 2da1d1f6f (Implement line-history search (git log -L), 2013-03-28). Interestingly, that commit already contained a canned test case covering a similar scenario: "-L '/long f/',/^}/:a.c -L /main/,/^}/:a.c simple" This test case looks for two line ranges in the same file, and both trace back disjointly to the test repository's inital commit, therefore changes to both line ranges should have been shown for the initial commit, but only changes for the first line range are shown. So this test case should have failed from the very beginning, but it never did, because, unfortunately, the canned expected result is incorrect, as it doesn't include changes for the second line range. A similar test with a similarly incorrect canned expected result was added later in 209618860c (log -L: fix overlapping input ranges, 2013-04-05). Correct these two canned expected results to contain the changes for the second line range for the initial commit as well. Signed-off-by: SZEDER Gábor Signed-off-by: Junio C Hamano --- line-log.c | 9 +++++++++ t/t4211/sha1/expect.multiple | 6 ++++++ t/t4211/sha1/expect.two-ranges | 6 ++++++ t/t4211/sha256/expect.multiple | 6 ++++++ t/t4211/sha256/expect.two-ranges | 6 ++++++ 5 files changed, 33 insertions(+) diff --git a/line-log.c b/line-log.c index 9cb8ea1484..9b75b4ac39 100644 --- a/line-log.c +++ b/line-log.c @@ -939,6 +939,15 @@ static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *rang long t_cur = t_start; unsigned int j_last; + /* + * If a diff range touches multiple line ranges, then all + * those line ranges should be shown, so take a step back if + * the current line range is still in the previous diff range + * (even if only partially). + */ + if (j > 0 && diff->target.ranges[j-1].end > t_start) + j--; + while (j < diff->target.nr && diff->target.ranges[j].end < t_start) j++; if (j == diff->target.nr || diff->target.ranges[j].start >= t_end) diff --git a/t/t4211/sha1/expect.multiple b/t/t4211/sha1/expect.multiple index 76ad5b598c..1eee8a7801 100644 --- a/t/t4211/sha1/expect.multiple +++ b/t/t4211/sha1/expect.multiple @@ -102,3 +102,9 @@ diff --git a/a.c b/a.c + s++; + } +} +@@ -0,0 +16,5 @@ ++int main () ++{ ++ printf("%d\n", f(15)); ++ return 0; ++} diff --git a/t/t4211/sha1/expect.two-ranges b/t/t4211/sha1/expect.two-ranges index 6109aa0dce..c5164f3be3 100644 --- a/t/t4211/sha1/expect.two-ranges +++ b/t/t4211/sha1/expect.two-ranges @@ -100,3 +100,9 @@ diff --git a/a.c b/a.c + s++; + } +} +@@ -0,0 +16,5 @@ ++int main () ++{ ++ printf("%d\n", f(15)); ++ return 0; ++} diff --git a/t/t4211/sha256/expect.multiple b/t/t4211/sha256/expect.multiple index ca00409b9a..dbd987b74a 100644 --- a/t/t4211/sha256/expect.multiple +++ b/t/t4211/sha256/expect.multiple @@ -102,3 +102,9 @@ diff --git a/a.c b/a.c + s++; + } +} +@@ -0,0 +16,5 @@ ++int main () ++{ ++ printf("%d\n", f(15)); ++ return 0; ++} diff --git a/t/t4211/sha256/expect.two-ranges b/t/t4211/sha256/expect.two-ranges index af57c8b997..6a94d3b9cb 100644 --- a/t/t4211/sha256/expect.two-ranges +++ b/t/t4211/sha256/expect.two-ranges @@ -100,3 +100,9 @@ diff --git a/a.c b/a.c + s++; + } +} +@@ -0,0 +16,5 @@ ++int main () ++{ ++ printf("%d\n", f(15)); ++ return 0; ++}