Merge branch 'np/log-graph-octopus-fix' into maint

"git log --graph" showing an octopus merge sometimes miscounted the
number of display columns it is consuming to show the merge and its
parent commits, which has been corrected.

* np/log-graph-octopus-fix:
log: fix coloring of certain octopus merge shapes

diff --git a/graph.c b/graph.c
index e1f6d3bddb38aadd4e439aea30f542d286ecb98e..f53135485f565baf7a0de1a5e4cffe2a4b2b55bd 100644 (file)
--- a/graph.c
+++ b/graph.c
@@ -842,27 +842,55 @@ static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
 }
 
 /*
- * Draw an octopus merge and return the number of characters written.
+ * Draw the horizontal dashes of an octopus merge and return the number of
+ * characters written.
  */
 static int graph_draw_octopus_merge(struct git_graph *graph,
                                    struct strbuf *sb)
 {
        /*
-        * Here dashless_commits represents the number of parents
-        * which don't need to have dashes (because their edges fit
-        * neatly under the commit).
-        */
-       const int dashless_commits = 2;
-       int col_num, i;
-       int num_dashes =
-               ((graph->num_parents - dashless_commits) * 2) - 1;
-       for (i = 0; i < num_dashes; i++) {
-               col_num = (i / 2) + dashless_commits + graph->commit_index;
-               strbuf_write_column(sb, &graph->new_columns[col_num], '-');
+        * Here dashless_parents represents the number of parents which don't
+        * need to have dashes (the edges labeled "0" and "1").  And
+        * dashful_parents are the remaining ones.
+        *
+        * | *---.
+        * | |\ \ \
+        * | | | | |
+        * x 0 1 2 3
+        *
+        */
+       const int dashless_parents = 2;
+       int dashful_parents = graph->num_parents - dashless_parents;
+
+       /*
+        * Usually, we add one new column for each parent (like the diagram
+        * above) but sometimes the first parent goes into an existing column,
+        * like this:
+        *
+        * | *---.
+        * | |\ \ \
+        * |/ / / /
+        * x 0 1 2
+        *
+        * In which case the number of parents will be one greater than the
+        * number of added columns.
+        */
+       int added_cols = (graph->num_new_columns - graph->num_columns);
+       int parent_in_old_cols = graph->num_parents - added_cols;
+
+       /*
+        * In both cases, commit_index corresponds to the edge labeled "0".
+        */
+       int first_col = graph->commit_index + dashless_parents
+           - parent_in_old_cols;
+
+       int i;
+       for (i = 0; i < dashful_parents; i++) {
+               strbuf_write_column(sb, &graph->new_columns[i+first_col], '-');
+               strbuf_write_column(sb, &graph->new_columns[i+first_col],
+                                   i == dashful_parents-1 ? '.' : '-');
        }
-       col_num = (i / 2) + dashless_commits + graph->commit_index;
-       strbuf_write_column(sb, &graph->new_columns[col_num], '.');
-       return num_dashes + 1;
+       return 2 * dashful_parents;
 }
 
 static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)

diff --git a/t/t4214-log-graph-octopus.sh b/t/t4214-log-graph-octopus.sh
new file mode 100755 (executable)
index 0000000..dab96c8
--- /dev/null
+++ b/t/t4214-log-graph-octopus.sh
@@ -0,0 +1,102 @@
+#!/bin/sh
+
+test_description='git log --graph of skewed left octopus merge.'
+
+. ./test-lib.sh
+
+test_expect_success 'set up merge history' '
+       cat >expect.uncolored <<-\EOF &&
+       * left
+       | *---.   octopus-merge
+       | |\ \ \
+       |/ / / /
+       | | | * 4
+       | | * | 3
+       | | |/
+       | * | 2
+       | |/
+       * | 1
+       |/
+       * initial
+       EOF
+       cat >expect.colors <<-\EOF &&
+       * left
+       <RED>|<RESET> *<BLUE>-<RESET><BLUE>-<RESET><MAGENTA>-<RESET><MAGENTA>.<RESET>   octopus-merge
+       <RED>|<RESET> <RED>|<RESET><YELLOW>\<RESET> <BLUE>\<RESET> <MAGENTA>\<RESET>
+       <RED>|<RESET><RED>/<RESET> <YELLOW>/<RESET> <BLUE>/<RESET> <MAGENTA>/<RESET>
+       <RED>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET> * 4
+       <RED>|<RESET> <YELLOW>|<RESET> * <MAGENTA>|<RESET> 3
+       <RED>|<RESET> <YELLOW>|<RESET> <MAGENTA>|<RESET><MAGENTA>/<RESET>
+       <RED>|<RESET> * <MAGENTA>|<RESET> 2
+       <RED>|<RESET> <MAGENTA>|<RESET><MAGENTA>/<RESET>
+       * <MAGENTA>|<RESET> 1
+       <MAGENTA>|<RESET><MAGENTA>/<RESET>
+       * initial
+       EOF
+       test_commit initial &&
+       for i in 1 2 3 4 ; do
+               git checkout master -b $i || return $?
+               # Make tag name different from branch name, to avoid
+               # ambiguity error when calling checkout.
+               test_commit $i $i $i tag$i || return $?
+       done &&
+       git checkout 1 -b merge &&
+       test_tick &&
+       git merge -m octopus-merge 1 2 3 4 &&
+       git checkout 1 -b L &&
+       test_commit left
+'
+
+test_expect_success 'log --graph with tricky octopus merge with colors' '
+       test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+       git log --color=always --graph --date-order --pretty=tformat:%s --all >actual.colors.raw &&
+       test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
+       test_cmp expect.colors actual.colors
+'
+
+test_expect_success 'log --graph with tricky octopus merge, no color' '
+       git log --color=never --graph --date-order --pretty=tformat:%s --all >actual.raw &&
+       sed "s/ *\$//" actual.raw >actual &&
+       test_cmp expect.uncolored actual
+'
+
+# Repeat the previous two tests with "normal" octopus merge (i.e.,
+# without the first parent skewing to the "left" branch column).
+
+test_expect_success 'log --graph with normal octopus merge, no color' '
+       cat >expect.uncolored <<-\EOF &&
+       *---.   octopus-merge
+       |\ \ \
+       | | | * 4
+       | | * | 3
+       | | |/
+       | * | 2
+       | |/
+       * | 1
+       |/
+       * initial
+       EOF
+       git log --color=never --graph --date-order --pretty=tformat:%s merge >actual.raw &&
+       sed "s/ *\$//" actual.raw >actual &&
+       test_cmp expect.uncolored actual
+'
+
+test_expect_success 'log --graph with normal octopus merge with colors' '
+       cat >expect.colors <<-\EOF &&
+       *<YELLOW>-<RESET><YELLOW>-<RESET><BLUE>-<RESET><BLUE>.<RESET>   octopus-merge
+       <RED>|<RESET><GREEN>\<RESET> <YELLOW>\<RESET> <BLUE>\<RESET>
+       <RED>|<RESET> <GREEN>|<RESET> <YELLOW>|<RESET> * 4
+       <RED>|<RESET> <GREEN>|<RESET> * <BLUE>|<RESET> 3
+       <RED>|<RESET> <GREEN>|<RESET> <BLUE>|<RESET><BLUE>/<RESET>
+       <RED>|<RESET> * <BLUE>|<RESET> 2
+       <RED>|<RESET> <BLUE>|<RESET><BLUE>/<RESET>
+       * <BLUE>|<RESET> 1
+       <BLUE>|<RESET><BLUE>/<RESET>
+       * initial
+       EOF
+       test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+       git log --color=always --graph --date-order --pretty=tformat:%s merge >actual.colors.raw &&
+       test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
+       test_cmp expect.colors actual.colors
+'
+test_done