diff.c: add a blocks mode for moved code detection

The new "blocks" mode provides a middle ground between plain and zebra.
It is as intuitive (few colors) as plain, but still has the requirement
for a minimum of lines/characters to count a block as moved.

Suggested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
(https://public-inbox.org/git/87o9j0uljo.fsf@evledraar.gmail.com/)
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index e3a44f03cdcee92098287bfccc9801fde042ef2b..ba56169de311fffd28134f43cffddaf66e731222 100644 (file)
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -276,10 +276,14 @@ plain::
        that are added somewhere else in the diff. This mode picks up any
        moved line, but it is not very useful in a review to determine
        if a block of code was moved without permutation.
        that are added somewhere else in the diff. This mode picks up any
        moved line, but it is not very useful in a review to determine
        if a block of code was moved without permutation.

-zebra::
+blocks::

        Blocks of moved text of at least 20 alphanumeric characters
        are detected greedily. The detected blocks are
        Blocks of moved text of at least 20 alphanumeric characters
        are detected greedily. The detected blocks are

-       painted using either the 'color.diff.{old,new}Moved' color or
+       painted using either the 'color.diff.{old,new}Moved' color.
+       Adjacent blocks cannot be told apart.
+zebra::
+       Blocks of moved text are detected as in 'blocks' mode. The blocks
+       are painted using either the 'color.diff.{old,new}Moved' color or

        'color.diff.{old,new}MovedAlternative'. The change between
        the two colors indicates that a new block was detected.
 dimmed_zebra::
        'color.diff.{old,new}MovedAlternative'. The change between
        the two colors indicates that a new block was detected.
 dimmed_zebra::

diff --git a/diff.c b/diff.c
index d1bae900cdccf3a2dd09ce8e09e317da8e587688..95c51c0b7df0fe68743dd571143196d5760d4abe 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -271,6 +271,8 @@ static int parse_color_moved(const char *arg)
                return COLOR_MOVED_NO;
        else if (!strcmp(arg, "plain"))
                return COLOR_MOVED_PLAIN;
                return COLOR_MOVED_NO;
        else if (!strcmp(arg, "plain"))
                return COLOR_MOVED_PLAIN;

+       else if (!strcmp(arg, "blocks"))
+               return COLOR_MOVED_BLOCKS;

        else if (!strcmp(arg, "zebra"))
                return COLOR_MOVED_ZEBRA;
        else if (!strcmp(arg, "default"))
        else if (!strcmp(arg, "zebra"))
                return COLOR_MOVED_ZEBRA;
        else if (!strcmp(arg, "default"))


@@ -278,7 +280,7 @@ static int parse_color_moved(const char *arg)
        else if (!strcmp(arg, "dimmed_zebra"))
                return COLOR_MOVED_ZEBRA_DIM;
        else
        else if (!strcmp(arg, "dimmed_zebra"))
                return COLOR_MOVED_ZEBRA_DIM;
        else

-               return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
+               return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed_zebra', 'plain'"));

 }
 
 int git_diff_ui_config(const char *var, const char *value, void *cb)
 }
 
 int git_diff_ui_config(const char *var, const char *value, void *cb)


@@ -903,7 +905,7 @@ static void mark_color_as_moved(struct diff_options *o,
 
                block_length++;
 
 
                block_length++;
 

-               if (flipped_block)
+               if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)

                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
        }
        adjust_last_block(o, n, block_length);
                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
        }
        adjust_last_block(o, n, block_length);

diff --git a/diff.h b/diff.h
index d29560f822ca0ee4738f769e2feb3939851d7ff1..7bd4f182c334f635e75760e96983bfd7e9ea795a 100644 (file)
--- a/diff.h
+++ b/diff.h
@@ -208,8 +208,9 @@ struct diff_options {
        enum {
                COLOR_MOVED_NO = 0,
                COLOR_MOVED_PLAIN = 1,
        enum {
                COLOR_MOVED_NO = 0,
                COLOR_MOVED_PLAIN = 1,

-               COLOR_MOVED_ZEBRA = 2,
-               COLOR_MOVED_ZEBRA_DIM = 3,
+               COLOR_MOVED_BLOCKS = 2,
+               COLOR_MOVED_ZEBRA = 3,
+               COLOR_MOVED_ZEBRA_DIM = 4,

        } color_moved;
        #define COLOR_MOVED_DEFAULT COLOR_MOVED_ZEBRA
        #define COLOR_MOVED_MIN_ALNUM_COUNT 20
        } color_moved;
        #define COLOR_MOVED_DEFAULT COLOR_MOVED_ZEBRA
        #define COLOR_MOVED_MIN_ALNUM_COUNT 20

diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index ddbc39013856ad0e85a7c65c14e8c00dc64116af..e54529f026dc4b64adefe8991025d8110c19acc2 100755 (executable)
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1223,7 +1223,7 @@ test_expect_success 'plain moved code, inside file' '
        test_cmp expected actual
 '
 
        test_cmp expected actual
 '
 

-test_expect_success 'detect permutations inside moved code -- dimmed_zebra' '
+test_expect_success 'detect blocks of moved code' '

        git reset --hard &&
        cat <<-\EOF >lines.txt &&
                long line 1
        git reset --hard &&
        cat <<-\EOF >lines.txt &&
                long line 1


@@ -1271,6 +1271,50 @@ test_expect_success 'detect permutations inside moved code -- dimmed_zebra' '
        test_config color.diff.newMovedDimmed "normal cyan" &&
        test_config color.diff.oldMovedAlternativeDimmed "normal blue" &&
        test_config color.diff.newMovedAlternativeDimmed "normal yellow" &&
        test_config color.diff.newMovedDimmed "normal cyan" &&
        test_config color.diff.oldMovedAlternativeDimmed "normal blue" &&
        test_config color.diff.newMovedAlternativeDimmed "normal yellow" &&

+       git diff HEAD --no-renames --color-moved=blocks --color >actual.raw &&
+       grep -v "index" actual.raw | test_decode_color >actual &&
+       cat <<-\EOF >expected &&
+       <BOLD>diff --git a/lines.txt b/lines.txt<RESET>
+       <BOLD>--- a/lines.txt<RESET>
+       <BOLD>+++ b/lines.txt<RESET>
+       <CYAN>@@ -1,16 +1,16 @@<RESET>
+       <MAGENTA>-long line 1<RESET>
+       <MAGENTA>-long line 2<RESET>
+       <MAGENTA>-long line 3<RESET>
+        line 4<RESET>
+        line 5<RESET>
+        line 6<RESET>
+        line 7<RESET>
+        line 8<RESET>
+        line 9<RESET>
+       <CYAN>+<RESET><CYAN>long line 1<RESET>
+       <CYAN>+<RESET><CYAN>long line 2<RESET>
+       <CYAN>+<RESET><CYAN>long line 3<RESET>
+       <CYAN>+<RESET><CYAN>long line 14<RESET>
+       <CYAN>+<RESET><CYAN>long line 15<RESET>
+       <CYAN>+<RESET><CYAN>long line 16<RESET>
+        line 10<RESET>
+        line 11<RESET>
+        line 12<RESET>
+        line 13<RESET>
+       <MAGENTA>-long line 14<RESET>
+       <MAGENTA>-long line 15<RESET>
+       <MAGENTA>-long line 16<RESET>
+       EOF
+       test_cmp expected actual
+
+'
+
+test_expect_success 'detect permutations inside moved code -- dimmed_zebra' '
+       # reuse setup from test before!
+       test_config color.diff.oldMoved "magenta" &&
+       test_config color.diff.newMoved "cyan" &&
+       test_config color.diff.oldMovedAlternative "blue" &&
+       test_config color.diff.newMovedAlternative "yellow" &&
+       test_config color.diff.oldMovedDimmed "normal magenta" &&
+       test_config color.diff.newMovedDimmed "normal cyan" &&
+       test_config color.diff.oldMovedAlternativeDimmed "normal blue" &&
+       test_config color.diff.newMovedAlternativeDimmed "normal yellow" &&

        git diff HEAD --no-renames --color-moved=dimmed_zebra --color >actual.raw &&
        grep -v "index" actual.raw | test_decode_color >actual &&
        cat <<-\EOF >expected &&
        git diff HEAD --no-renames --color-moved=dimmed_zebra --color >actual.raw &&
        grep -v "index" actual.raw | test_decode_color >actual &&
        cat <<-\EOF >expected &&


@@ -1669,7 +1713,8 @@ test_expect_success '--color-moved treats adjacent blocks as separate for MIN_AL
        7charsA
        EOF
 
        7charsA
        EOF
 

-       git diff HEAD --color-moved=zebra --color --no-renames | grep -v "index" | test_decode_color >actual &&
+       git diff HEAD --color-moved=zebra --color --no-renames >actual.raw &&
+       grep -v "index" actual.raw | test_decode_color >actual &&

        cat >expected <<-\EOF &&
        <BOLD>diff --git a/bar b/bar<RESET>
        <BOLD>--- a/bar<RESET>
        cat >expected <<-\EOF &&
        <BOLD>diff --git a/bar b/bar<RESET>
        <BOLD>--- a/bar<RESET>