git/t/t4215-log-skewed-merges.sh

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graph: example of graph output that can be simplified The commits following this one introduce a series of improvements to the layout of graphs, tidying up a few edge cases, namely: - merge whose first parent fuses with an existing column to the left - merge whose last parent fuses with its immediate neighbor on the right - edges that collapse to the left above and below a commit line This test case exemplifies these cases and provides a motivating example of the kind of history I'm aiming to clear up. The first parent of merge E is the same as the parent of H, so those edges fuse together. * H | | *-. E | |\ \ |/ / / | * B We can "skew" the display of this merge so that it doesn't introduce additional columns that immediately collapse: * H | | * E |/|\ | * B The last parent of E is D, the same as the parent of F which is the edge to the right of the merge. * F | \ *-. \ E |\ \ \ / / / / | / |/ * D The two edges leading to D could be fused sooner: rather than expanding the F edge around the merge and then letting the edges collapse, the F edge could fuse with the E edge in the post-merge line: * F | \ *-. | E |\ \| / / / | * D If this is combined with the "skew" effect above, we get a much cleaner graph display for these edges: * F | * | E /|\| | * D Finally, the edge leading from C to A appears jagged as it passes through the commit line for B: | * | C | |/ * | B |/ * A This can be smoothed out so that such edges are easier to read: | * | C | |/ * / B |/ * A Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:53 +00:00
#!/bin/sh
test_description='git log --graph of skewed merges'
. ./test-lib.sh
check_graph () {
cat >expect &&
git log --graph --pretty=tformat:%s "$@" >actual.raw &&
sed "s/ *$//" actual.raw >actual &&
test_cmp expect actual
}
graph: example of graph output that can be simplified The commits following this one introduce a series of improvements to the layout of graphs, tidying up a few edge cases, namely: - merge whose first parent fuses with an existing column to the left - merge whose last parent fuses with its immediate neighbor on the right - edges that collapse to the left above and below a commit line This test case exemplifies these cases and provides a motivating example of the kind of history I'm aiming to clear up. The first parent of merge E is the same as the parent of H, so those edges fuse together. * H | | *-. E | |\ \ |/ / / | * B We can "skew" the display of this merge so that it doesn't introduce additional columns that immediately collapse: * H | | * E |/|\ | * B The last parent of E is D, the same as the parent of F which is the edge to the right of the merge. * F | \ *-. \ E |\ \ \ / / / / | / |/ * D The two edges leading to D could be fused sooner: rather than expanding the F edge around the merge and then letting the edges collapse, the F edge could fuse with the E edge in the post-merge line: * F | \ *-. | E |\ \| / / / | * D If this is combined with the "skew" effect above, we get a much cleaner graph display for these edges: * F | * | E /|\| | * D Finally, the edge leading from C to A appears jagged as it passes through the commit line for B: | * | C | |/ * | B |/ * A This can be smoothed out so that such edges are easier to read: | * | C | |/ * / B |/ * A Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:53 +00:00
test_expect_success 'log --graph with merge fusing with its left and right neighbors' '
git checkout --orphan _p &&
test_commit A &&
test_commit B &&
git checkout -b _q @^ && test_commit C &&
git checkout -b _r @^ && test_commit D &&
git checkout _p && git merge --no-ff _q _r -m E &&
git checkout _r && test_commit F &&
git checkout _p && git merge --no-ff _r -m G &&
git checkout @^^ && git merge --no-ff _p -m H &&
check_graph <<-\EOF
graph: example of graph output that can be simplified The commits following this one introduce a series of improvements to the layout of graphs, tidying up a few edge cases, namely: - merge whose first parent fuses with an existing column to the left - merge whose last parent fuses with its immediate neighbor on the right - edges that collapse to the left above and below a commit line This test case exemplifies these cases and provides a motivating example of the kind of history I'm aiming to clear up. The first parent of merge E is the same as the parent of H, so those edges fuse together. * H | | *-. E | |\ \ |/ / / | * B We can "skew" the display of this merge so that it doesn't introduce additional columns that immediately collapse: * H | | * E |/|\ | * B The last parent of E is D, the same as the parent of F which is the edge to the right of the merge. * F | \ *-. \ E |\ \ \ / / / / | / |/ * D The two edges leading to D could be fused sooner: rather than expanding the F edge around the merge and then letting the edges collapse, the F edge could fuse with the E edge in the post-merge line: * F | \ *-. | E |\ \| / / / | * D If this is combined with the "skew" effect above, we get a much cleaner graph display for these edges: * F | * | E /|\| | * D Finally, the edge leading from C to A appears jagged as it passes through the commit line for B: | * | C | |/ * | B |/ * A This can be smoothed out so that such edges are easier to read: | * | C | |/ * / B |/ * A Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:53 +00:00
* H
|\
| * G
| |\
| | * F
| * | E
|/|\|
graph: example of graph output that can be simplified The commits following this one introduce a series of improvements to the layout of graphs, tidying up a few edge cases, namely: - merge whose first parent fuses with an existing column to the left - merge whose last parent fuses with its immediate neighbor on the right - edges that collapse to the left above and below a commit line This test case exemplifies these cases and provides a motivating example of the kind of history I'm aiming to clear up. The first parent of merge E is the same as the parent of H, so those edges fuse together. * H | | *-. E | |\ \ |/ / / | * B We can "skew" the display of this merge so that it doesn't introduce additional columns that immediately collapse: * H | | * E |/|\ | * B The last parent of E is D, the same as the parent of F which is the edge to the right of the merge. * F | \ *-. \ E |\ \ \ / / / / | / |/ * D The two edges leading to D could be fused sooner: rather than expanding the F edge around the merge and then letting the edges collapse, the F edge could fuse with the E edge in the post-merge line: * F | \ *-. | E |\ \| / / / | * D If this is combined with the "skew" effect above, we get a much cleaner graph display for these edges: * F | * | E /|\| | * D Finally, the edge leading from C to A appears jagged as it passes through the commit line for B: | * | C | |/ * | B |/ * A This can be smoothed out so that such edges are easier to read: | * | C | |/ * / B |/ * A Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:53 +00:00
| | * D
| * | C
| |/
* / B
graph: example of graph output that can be simplified The commits following this one introduce a series of improvements to the layout of graphs, tidying up a few edge cases, namely: - merge whose first parent fuses with an existing column to the left - merge whose last parent fuses with its immediate neighbor on the right - edges that collapse to the left above and below a commit line This test case exemplifies these cases and provides a motivating example of the kind of history I'm aiming to clear up. The first parent of merge E is the same as the parent of H, so those edges fuse together. * H | | *-. E | |\ \ |/ / / | * B We can "skew" the display of this merge so that it doesn't introduce additional columns that immediately collapse: * H | | * E |/|\ | * B The last parent of E is D, the same as the parent of F which is the edge to the right of the merge. * F | \ *-. \ E |\ \ \ / / / / | / |/ * D The two edges leading to D could be fused sooner: rather than expanding the F edge around the merge and then letting the edges collapse, the F edge could fuse with the E edge in the post-merge line: * F | \ *-. | E |\ \| / / / | * D If this is combined with the "skew" effect above, we get a much cleaner graph display for these edges: * F | * | E /|\| | * D Finally, the edge leading from C to A appears jagged as it passes through the commit line for B: | * | C | |/ * | B |/ * A This can be smoothed out so that such edges are easier to read: | * | C | |/ * / B |/ * A Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:53 +00:00
|/
* A
EOF
'
test_expect_success 'log --graph with left-skewed merge' '
git checkout --orphan 0_p && test_commit 0_A &&
git checkout -b 0_q 0_p && test_commit 0_B &&
git checkout -b 0_r 0_p &&
test_commit 0_C &&
test_commit 0_D &&
git checkout -b 0_s 0_p && test_commit 0_E &&
git checkout -b 0_t 0_p && git merge --no-ff 0_r^ 0_s -m 0_F &&
git checkout 0_p && git merge --no-ff 0_s -m 0_G &&
git checkout @^ && git merge --no-ff 0_q 0_r 0_t 0_p -m 0_H &&
check_graph <<-\EOF
*-----. 0_H
|\ \ \ \
| | | | * 0_G
| |_|_|/|
|/| | | |
| | | * | 0_F
| |_|/|\|
|/| | | |
| | | | * 0_E
| |_|_|/
|/| | |
| | * | 0_D
| | |/
| | * 0_C
| |/
|/|
| * 0_B
|/
* 0_A
EOF
'
graph: commit and post-merge lines for left-skewed merges Following the introduction of "left-skewed" merges, which are merges whose first parent fuses with another edge to its left, we have some more edge cases to deal with in the display of commit and post-merge lines. The current graph code handles the following cases for edges appearing to the right of the commit (*) on commit lines. A 2-way merge is usually followed by vertical lines: | | | | * | | |\ \ An octopus merge (more than two parents) is always followed by edges sloping to the right: | | \ | | \ | *-. \ | *---. \ | |\ \ \ | |\ \ \ \ A 2-way merge is followed by a right-sloping edge if the commit line immediately follows a post-merge line for a commit that appears in the same column as the current commit, or any column to the left of that: | * | * | | |\ | |\ \ | * \ | | * \ | |\ \ | | |\ \ This commit introduces the following new cases for commit lines. If a 2-way merge skews to the left, then the edges to its right are always vertical lines, even if the commit follows a post-merge line: | | | | |\ | * | | * | |/| | |/| | A commit with 3 parents that skews left is followed by vertical edges: | | | | * | |/|\ \ If a 3-way left-skewed merge commit appears immediately after a post-merge line, then it may be followed the right-sloping edges, just like a 2-way merge that is not skewed. | |\ | * \ |/|\ \ Octopus merges with 4 or more parents that skew to the left will always be followed by right-sloping edges, because the existing columns need to expand around the merge. | | \ | *-. \ |/|\ \ \ On post-merge lines, usually all edges following the current commit slope to the right: | * | | | |\ \ \ However, if the commit is a left-skewed 2-way merge, the edges to its right remain vertical. We also need to display a space after the vertical line descending from the commit marker, whereas this line would normally be followed by a backslash. | * | | |/| | | If a left-skewed merge has more than 2 parents, then the edges to its right are still sloped as they bend around the edges introduced by the merge. | * | | |/|\ \ \ To handle these new cases, we need to know not just how many parents each commit has, but how many new columns it adds to the display; this quantity is recorded in the `edges_added` field for the current commit, and `prev_edges_added` field for the previous commit. Here, "column" refers to visual columns, not the logical columns of the `columns` array. This is because even if all the commit's parents end up fusing with existing edges, they initially introduce distinct edges in the commit and post-merge lines before those edges collapse. For example, a 3-way merge whose 2nd and 3rd parents fuse with existing edges still introduces 2 visual columns that affect the display of edges to their right. | | | \ | | *-. \ | | |\ \ \ | |_|/ / / |/| | / / | | |/ / | |/| | | | | | This merge does not introduce any *logical* columns; there are 4 edges before and after this commit once all edges have collapsed. But it does initially introduce 2 new edges that need to be accommodated by the edges to their right. Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:55 +00:00
test_expect_success 'log --graph with nested left-skewed merge' '
git checkout --orphan 1_p &&
test_commit 1_A &&
test_commit 1_B &&
test_commit 1_C &&
git checkout -b 1_q @^ && test_commit 1_D &&
git checkout 1_p && git merge --no-ff 1_q -m 1_E &&
git checkout -b 1_r @~3 && test_commit 1_F &&
git checkout 1_p && git merge --no-ff 1_r -m 1_G &&
git checkout @^^ && git merge --no-ff 1_p -m 1_H &&
check_graph <<-\EOF
graph: commit and post-merge lines for left-skewed merges Following the introduction of "left-skewed" merges, which are merges whose first parent fuses with another edge to its left, we have some more edge cases to deal with in the display of commit and post-merge lines. The current graph code handles the following cases for edges appearing to the right of the commit (*) on commit lines. A 2-way merge is usually followed by vertical lines: | | | | * | | |\ \ An octopus merge (more than two parents) is always followed by edges sloping to the right: | | \ | | \ | *-. \ | *---. \ | |\ \ \ | |\ \ \ \ A 2-way merge is followed by a right-sloping edge if the commit line immediately follows a post-merge line for a commit that appears in the same column as the current commit, or any column to the left of that: | * | * | | |\ | |\ \ | * \ | | * \ | |\ \ | | |\ \ This commit introduces the following new cases for commit lines. If a 2-way merge skews to the left, then the edges to its right are always vertical lines, even if the commit follows a post-merge line: | | | | |\ | * | | * | |/| | |/| | A commit with 3 parents that skews left is followed by vertical edges: | | | | * | |/|\ \ If a 3-way left-skewed merge commit appears immediately after a post-merge line, then it may be followed the right-sloping edges, just like a 2-way merge that is not skewed. | |\ | * \ |/|\ \ Octopus merges with 4 or more parents that skew to the left will always be followed by right-sloping edges, because the existing columns need to expand around the merge. | | \ | *-. \ |/|\ \ \ On post-merge lines, usually all edges following the current commit slope to the right: | * | | | |\ \ \ However, if the commit is a left-skewed 2-way merge, the edges to its right remain vertical. We also need to display a space after the vertical line descending from the commit marker, whereas this line would normally be followed by a backslash. | * | | |/| | | If a left-skewed merge has more than 2 parents, then the edges to its right are still sloped as they bend around the edges introduced by the merge. | * | | |/|\ \ \ To handle these new cases, we need to know not just how many parents each commit has, but how many new columns it adds to the display; this quantity is recorded in the `edges_added` field for the current commit, and `prev_edges_added` field for the previous commit. Here, "column" refers to visual columns, not the logical columns of the `columns` array. This is because even if all the commit's parents end up fusing with existing edges, they initially introduce distinct edges in the commit and post-merge lines before those edges collapse. For example, a 3-way merge whose 2nd and 3rd parents fuse with existing edges still introduces 2 visual columns that affect the display of edges to their right. | | | \ | | *-. \ | | |\ \ \ | |_|/ / / |/| | / / | | |/ / | |/| | | | | | This merge does not introduce any *logical* columns; there are 4 edges before and after this commit once all edges have collapsed. But it does initially introduce 2 new edges that need to be accommodated by the edges to their right. Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:55 +00:00
* 1_H
|\
| * 1_G
| |\
| | * 1_F
| * | 1_E
|/| |
| * | 1_D
* | | 1_C
|/ /
* / 1_B
graph: commit and post-merge lines for left-skewed merges Following the introduction of "left-skewed" merges, which are merges whose first parent fuses with another edge to its left, we have some more edge cases to deal with in the display of commit and post-merge lines. The current graph code handles the following cases for edges appearing to the right of the commit (*) on commit lines. A 2-way merge is usually followed by vertical lines: | | | | * | | |\ \ An octopus merge (more than two parents) is always followed by edges sloping to the right: | | \ | | \ | *-. \ | *---. \ | |\ \ \ | |\ \ \ \ A 2-way merge is followed by a right-sloping edge if the commit line immediately follows a post-merge line for a commit that appears in the same column as the current commit, or any column to the left of that: | * | * | | |\ | |\ \ | * \ | | * \ | |\ \ | | |\ \ This commit introduces the following new cases for commit lines. If a 2-way merge skews to the left, then the edges to its right are always vertical lines, even if the commit follows a post-merge line: | | | | |\ | * | | * | |/| | |/| | A commit with 3 parents that skews left is followed by vertical edges: | | | | * | |/|\ \ If a 3-way left-skewed merge commit appears immediately after a post-merge line, then it may be followed the right-sloping edges, just like a 2-way merge that is not skewed. | |\ | * \ |/|\ \ Octopus merges with 4 or more parents that skew to the left will always be followed by right-sloping edges, because the existing columns need to expand around the merge. | | \ | *-. \ |/|\ \ \ On post-merge lines, usually all edges following the current commit slope to the right: | * | | | |\ \ \ However, if the commit is a left-skewed 2-way merge, the edges to its right remain vertical. We also need to display a space after the vertical line descending from the commit marker, whereas this line would normally be followed by a backslash. | * | | |/| | | If a left-skewed merge has more than 2 parents, then the edges to its right are still sloped as they bend around the edges introduced by the merge. | * | | |/|\ \ \ To handle these new cases, we need to know not just how many parents each commit has, but how many new columns it adds to the display; this quantity is recorded in the `edges_added` field for the current commit, and `prev_edges_added` field for the previous commit. Here, "column" refers to visual columns, not the logical columns of the `columns` array. This is because even if all the commit's parents end up fusing with existing edges, they initially introduce distinct edges in the commit and post-merge lines before those edges collapse. For example, a 3-way merge whose 2nd and 3rd parents fuse with existing edges still introduces 2 visual columns that affect the display of edges to their right. | | | \ | | *-. \ | | |\ \ \ | |_|/ / / |/| | / / | | |/ / | |/| | | | | | This merge does not introduce any *logical* columns; there are 4 edges before and after this commit once all edges have collapsed. But it does initially introduce 2 new edges that need to be accommodated by the edges to their right. Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:55 +00:00
|/
* 1_A
EOF
'
test_expect_success 'log --graph with nested left-skewed merge following normal merge' '
git checkout --orphan 2_p &&
test_commit 2_A &&
test_commit 2_B &&
test_commit 2_C &&
git checkout -b 2_q @^^ &&
test_commit 2_D &&
test_commit 2_E &&
git checkout -b 2_r @^ && test_commit 2_F &&
git checkout 2_q &&
git merge --no-ff 2_r -m 2_G &&
git merge --no-ff 2_p^ -m 2_H &&
git checkout -b 2_s @^^ && git merge --no-ff 2_q -m 2_J &&
git checkout 2_p && git merge --no-ff 2_s -m 2_K &&
check_graph <<-\EOF
graph: commit and post-merge lines for left-skewed merges Following the introduction of "left-skewed" merges, which are merges whose first parent fuses with another edge to its left, we have some more edge cases to deal with in the display of commit and post-merge lines. The current graph code handles the following cases for edges appearing to the right of the commit (*) on commit lines. A 2-way merge is usually followed by vertical lines: | | | | * | | |\ \ An octopus merge (more than two parents) is always followed by edges sloping to the right: | | \ | | \ | *-. \ | *---. \ | |\ \ \ | |\ \ \ \ A 2-way merge is followed by a right-sloping edge if the commit line immediately follows a post-merge line for a commit that appears in the same column as the current commit, or any column to the left of that: | * | * | | |\ | |\ \ | * \ | | * \ | |\ \ | | |\ \ This commit introduces the following new cases for commit lines. If a 2-way merge skews to the left, then the edges to its right are always vertical lines, even if the commit follows a post-merge line: | | | | |\ | * | | * | |/| | |/| | A commit with 3 parents that skews left is followed by vertical edges: | | | | * | |/|\ \ If a 3-way left-skewed merge commit appears immediately after a post-merge line, then it may be followed the right-sloping edges, just like a 2-way merge that is not skewed. | |\ | * \ |/|\ \ Octopus merges with 4 or more parents that skew to the left will always be followed by right-sloping edges, because the existing columns need to expand around the merge. | | \ | *-. \ |/|\ \ \ On post-merge lines, usually all edges following the current commit slope to the right: | * | | | |\ \ \ However, if the commit is a left-skewed 2-way merge, the edges to its right remain vertical. We also need to display a space after the vertical line descending from the commit marker, whereas this line would normally be followed by a backslash. | * | | |/| | | If a left-skewed merge has more than 2 parents, then the edges to its right are still sloped as they bend around the edges introduced by the merge. | * | | |/|\ \ \ To handle these new cases, we need to know not just how many parents each commit has, but how many new columns it adds to the display; this quantity is recorded in the `edges_added` field for the current commit, and `prev_edges_added` field for the previous commit. Here, "column" refers to visual columns, not the logical columns of the `columns` array. This is because even if all the commit's parents end up fusing with existing edges, they initially introduce distinct edges in the commit and post-merge lines before those edges collapse. For example, a 3-way merge whose 2nd and 3rd parents fuse with existing edges still introduces 2 visual columns that affect the display of edges to their right. | | | \ | | *-. \ | | |\ \ \ | |_|/ / / |/| | / / | | |/ / | |/| | | | | | This merge does not introduce any *logical* columns; there are 4 edges before and after this commit once all edges have collapsed. But it does initially introduce 2 new edges that need to be accommodated by the edges to their right. Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:55 +00:00
* 2_K
|\
| * 2_J
| |\
| | * 2_H
| | |\
| | * | 2_G
| |/| |
| | * | 2_F
| * | | 2_E
| |/ /
| * | 2_D
* | | 2_C
| |/
|/|
* | 2_B
|/
* 2_A
EOF
'
test_expect_success 'log --graph with nested right-skewed merge following left-skewed merge' '
git checkout --orphan 3_p &&
test_commit 3_A &&
git checkout -b 3_q &&
test_commit 3_B &&
test_commit 3_C &&
git checkout -b 3_r @^ &&
test_commit 3_D &&
git checkout 3_q && git merge --no-ff 3_r -m 3_E &&
git checkout 3_p && git merge --no-ff 3_q -m 3_F &&
git checkout 3_r && test_commit 3_G &&
git checkout 3_p && git merge --no-ff 3_r -m 3_H &&
git checkout @^^ && git merge --no-ff 3_p -m 3_J &&
check_graph <<-\EOF
graph: commit and post-merge lines for left-skewed merges Following the introduction of "left-skewed" merges, which are merges whose first parent fuses with another edge to its left, we have some more edge cases to deal with in the display of commit and post-merge lines. The current graph code handles the following cases for edges appearing to the right of the commit (*) on commit lines. A 2-way merge is usually followed by vertical lines: | | | | * | | |\ \ An octopus merge (more than two parents) is always followed by edges sloping to the right: | | \ | | \ | *-. \ | *---. \ | |\ \ \ | |\ \ \ \ A 2-way merge is followed by a right-sloping edge if the commit line immediately follows a post-merge line for a commit that appears in the same column as the current commit, or any column to the left of that: | * | * | | |\ | |\ \ | * \ | | * \ | |\ \ | | |\ \ This commit introduces the following new cases for commit lines. If a 2-way merge skews to the left, then the edges to its right are always vertical lines, even if the commit follows a post-merge line: | | | | |\ | * | | * | |/| | |/| | A commit with 3 parents that skews left is followed by vertical edges: | | | | * | |/|\ \ If a 3-way left-skewed merge commit appears immediately after a post-merge line, then it may be followed the right-sloping edges, just like a 2-way merge that is not skewed. | |\ | * \ |/|\ \ Octopus merges with 4 or more parents that skew to the left will always be followed by right-sloping edges, because the existing columns need to expand around the merge. | | \ | *-. \ |/|\ \ \ On post-merge lines, usually all edges following the current commit slope to the right: | * | | | |\ \ \ However, if the commit is a left-skewed 2-way merge, the edges to its right remain vertical. We also need to display a space after the vertical line descending from the commit marker, whereas this line would normally be followed by a backslash. | * | | |/| | | If a left-skewed merge has more than 2 parents, then the edges to its right are still sloped as they bend around the edges introduced by the merge. | * | | |/|\ \ \ To handle these new cases, we need to know not just how many parents each commit has, but how many new columns it adds to the display; this quantity is recorded in the `edges_added` field for the current commit, and `prev_edges_added` field for the previous commit. Here, "column" refers to visual columns, not the logical columns of the `columns` array. This is because even if all the commit's parents end up fusing with existing edges, they initially introduce distinct edges in the commit and post-merge lines before those edges collapse. For example, a 3-way merge whose 2nd and 3rd parents fuse with existing edges still introduces 2 visual columns that affect the display of edges to their right. | | | \ | | *-. \ | | |\ \ \ | |_|/ / / |/| | / / | | |/ / | |/| | | | | | This merge does not introduce any *logical* columns; there are 4 edges before and after this commit once all edges have collapsed. But it does initially introduce 2 new edges that need to be accommodated by the edges to their right. Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:55 +00:00
* 3_J
|\
| * 3_H
| |\
| | * 3_G
| * | 3_F
|/| |
| * | 3_E
| |\|
graph: commit and post-merge lines for left-skewed merges Following the introduction of "left-skewed" merges, which are merges whose first parent fuses with another edge to its left, we have some more edge cases to deal with in the display of commit and post-merge lines. The current graph code handles the following cases for edges appearing to the right of the commit (*) on commit lines. A 2-way merge is usually followed by vertical lines: | | | | * | | |\ \ An octopus merge (more than two parents) is always followed by edges sloping to the right: | | \ | | \ | *-. \ | *---. \ | |\ \ \ | |\ \ \ \ A 2-way merge is followed by a right-sloping edge if the commit line immediately follows a post-merge line for a commit that appears in the same column as the current commit, or any column to the left of that: | * | * | | |\ | |\ \ | * \ | | * \ | |\ \ | | |\ \ This commit introduces the following new cases for commit lines. If a 2-way merge skews to the left, then the edges to its right are always vertical lines, even if the commit follows a post-merge line: | | | | |\ | * | | * | |/| | |/| | A commit with 3 parents that skews left is followed by vertical edges: | | | | * | |/|\ \ If a 3-way left-skewed merge commit appears immediately after a post-merge line, then it may be followed the right-sloping edges, just like a 2-way merge that is not skewed. | |\ | * \ |/|\ \ Octopus merges with 4 or more parents that skew to the left will always be followed by right-sloping edges, because the existing columns need to expand around the merge. | | \ | *-. \ |/|\ \ \ On post-merge lines, usually all edges following the current commit slope to the right: | * | | | |\ \ \ However, if the commit is a left-skewed 2-way merge, the edges to its right remain vertical. We also need to display a space after the vertical line descending from the commit marker, whereas this line would normally be followed by a backslash. | * | | |/| | | If a left-skewed merge has more than 2 parents, then the edges to its right are still sloped as they bend around the edges introduced by the merge. | * | | |/|\ \ \ To handle these new cases, we need to know not just how many parents each commit has, but how many new columns it adds to the display; this quantity is recorded in the `edges_added` field for the current commit, and `prev_edges_added` field for the previous commit. Here, "column" refers to visual columns, not the logical columns of the `columns` array. This is because even if all the commit's parents end up fusing with existing edges, they initially introduce distinct edges in the commit and post-merge lines before those edges collapse. For example, a 3-way merge whose 2nd and 3rd parents fuse with existing edges still introduces 2 visual columns that affect the display of edges to their right. | | | \ | | *-. \ | | |\ \ \ | |_|/ / / |/| | / / | | |/ / | |/| | | | | | This merge does not introduce any *logical* columns; there are 4 edges before and after this commit once all edges have collapsed. But it does initially introduce 2 new edges that need to be accommodated by the edges to their right. Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:55 +00:00
| | * 3_D
| * | 3_C
| |/
| * 3_B
|/
* 3_A
EOF
'
test_expect_success 'log --graph with right-skewed merge following a left-skewed one' '
git checkout --orphan 4_p &&
test_commit 4_A &&
test_commit 4_B &&
test_commit 4_C &&
git checkout -b 4_q @^^ && test_commit 4_D &&
git checkout -b 4_r 4_p^ && git merge --no-ff 4_q -m 4_E &&
git checkout -b 4_s 4_p^^ &&
git merge --no-ff 4_r -m 4_F &&
git merge --no-ff 4_p -m 4_G &&
git checkout @^^ && git merge --no-ff 4_s -m 4_H &&
check_graph --date-order <<-\EOF
graph: commit and post-merge lines for left-skewed merges Following the introduction of "left-skewed" merges, which are merges whose first parent fuses with another edge to its left, we have some more edge cases to deal with in the display of commit and post-merge lines. The current graph code handles the following cases for edges appearing to the right of the commit (*) on commit lines. A 2-way merge is usually followed by vertical lines: | | | | * | | |\ \ An octopus merge (more than two parents) is always followed by edges sloping to the right: | | \ | | \ | *-. \ | *---. \ | |\ \ \ | |\ \ \ \ A 2-way merge is followed by a right-sloping edge if the commit line immediately follows a post-merge line for a commit that appears in the same column as the current commit, or any column to the left of that: | * | * | | |\ | |\ \ | * \ | | * \ | |\ \ | | |\ \ This commit introduces the following new cases for commit lines. If a 2-way merge skews to the left, then the edges to its right are always vertical lines, even if the commit follows a post-merge line: | | | | |\ | * | | * | |/| | |/| | A commit with 3 parents that skews left is followed by vertical edges: | | | | * | |/|\ \ If a 3-way left-skewed merge commit appears immediately after a post-merge line, then it may be followed the right-sloping edges, just like a 2-way merge that is not skewed. | |\ | * \ |/|\ \ Octopus merges with 4 or more parents that skew to the left will always be followed by right-sloping edges, because the existing columns need to expand around the merge. | | \ | *-. \ |/|\ \ \ On post-merge lines, usually all edges following the current commit slope to the right: | * | | | |\ \ \ However, if the commit is a left-skewed 2-way merge, the edges to its right remain vertical. We also need to display a space after the vertical line descending from the commit marker, whereas this line would normally be followed by a backslash. | * | | |/| | | If a left-skewed merge has more than 2 parents, then the edges to its right are still sloped as they bend around the edges introduced by the merge. | * | | |/|\ \ \ To handle these new cases, we need to know not just how many parents each commit has, but how many new columns it adds to the display; this quantity is recorded in the `edges_added` field for the current commit, and `prev_edges_added` field for the previous commit. Here, "column" refers to visual columns, not the logical columns of the `columns` array. This is because even if all the commit's parents end up fusing with existing edges, they initially introduce distinct edges in the commit and post-merge lines before those edges collapse. For example, a 3-way merge whose 2nd and 3rd parents fuse with existing edges still introduces 2 visual columns that affect the display of edges to their right. | | | \ | | *-. \ | | |\ \ \ | |_|/ / / |/| | / / | | |/ / | |/| | | | | | This merge does not introduce any *logical* columns; there are 4 edges before and after this commit once all edges have collapsed. But it does initially introduce 2 new edges that need to be accommodated by the edges to their right. Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:55 +00:00
* 4_H
|\
| * 4_G
| |\
| * | 4_F
|/| |
| * | 4_E
| |\ \
| | * | 4_D
| |/ /
|/| |
| | * 4_C
| |/
| * 4_B
|/
* 4_A
EOF
'
test_expect_success 'log --graph with octopus merge with column joining its penultimate parent' '
git checkout --orphan 5_p &&
test_commit 5_A &&
git branch 5_q &&
git branch 5_r &&
test_commit 5_B &&
git checkout 5_q && test_commit 5_C &&
git checkout 5_r && test_commit 5_D &&
git checkout 5_p &&
git merge --no-ff 5_q 5_r -m 5_E &&
git checkout 5_q && test_commit 5_F &&
git checkout -b 5_s 5_p^ &&
git merge --no-ff 5_p 5_q -m 5_G &&
git checkout 5_r &&
git merge --no-ff 5_s -m 5_H &&
check_graph <<-\EOF
* 5_H
|\
| *-. 5_G
| |\ \
| | | * 5_F
| | * | 5_E
| |/|\ \
| |_|/ /
|/| | /
| | |/
* | | 5_D
| | * 5_C
| |/
|/|
| * 5_B
|/
* 5_A
EOF
'
graph: example of graph output that can be simplified The commits following this one introduce a series of improvements to the layout of graphs, tidying up a few edge cases, namely: - merge whose first parent fuses with an existing column to the left - merge whose last parent fuses with its immediate neighbor on the right - edges that collapse to the left above and below a commit line This test case exemplifies these cases and provides a motivating example of the kind of history I'm aiming to clear up. The first parent of merge E is the same as the parent of H, so those edges fuse together. * H | | *-. E | |\ \ |/ / / | * B We can "skew" the display of this merge so that it doesn't introduce additional columns that immediately collapse: * H | | * E |/|\ | * B The last parent of E is D, the same as the parent of F which is the edge to the right of the merge. * F | \ *-. \ E |\ \ \ / / / / | / |/ * D The two edges leading to D could be fused sooner: rather than expanding the F edge around the merge and then letting the edges collapse, the F edge could fuse with the E edge in the post-merge line: * F | \ *-. | E |\ \| / / / | * D If this is combined with the "skew" effect above, we get a much cleaner graph display for these edges: * F | * | E /|\| | * D Finally, the edge leading from C to A appears jagged as it passes through the commit line for B: | * | C | |/ * | B |/ * A This can be smoothed out so that such edges are easier to read: | * | C | |/ * / B |/ * A Signed-off-by: James Coglan <jcoglan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15 23:47:53 +00:00
test_done