Merge branch 'jc/diff-irreversible-delete'

* jc/diff-irreversible-delete:
git diff -D: omit the preimage of deletes

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 7e4bd425e1fec23bbca0e89a0d7b4f53cf4f4483..34f01458c296ce68bcba4c08177aba127fc2333b 100644 (file)
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -263,6 +263,19 @@ endif::git-log[]
        projects, so use it with caution.  Giving more than one
        `-C` option has the same effect.
 
+-D::
+--irreversible-delete::
+       Omit the preimage for deletes, i.e. print only the header but not
+       the diff between the preimage and `/dev/null`. The resulting patch
+       is not meant to be applied with `patch` nor `git apply`; this is
+       solely for people who want to just concentrate on reviewing the
+       text after the change. In addition, the output obviously lack
+       enough information to apply such a patch in reverse, even manually,
+       hence the name of the option.
++
+When used together with `-B`, omit also the preimage in the deletion part
+of a delete/create pair.
+
 -l<num>::
        The `-M` and `-C` options require O(n^2) processing time where n
        is the number of potential rename/copy targets.  This

diff --git a/diff.c b/diff.c
index 56758c7dca3e7529cbb050afd792425a45d05517..3b40e597d5793d13944f9604e5197ac216eb3a3e 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -581,11 +581,14 @@ static void emit_rewrite_diff(const char *name_a,
                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
                line_prefix, fraginfo);
-       print_line_count(o->file, lc_a);
+       if (!o->irreversible_delete)
+               print_line_count(o->file, lc_a);
+       else
+               fprintf(o->file, "?,?");
        fprintf(o->file, " +");
        print_line_count(o->file, lc_b);
        fprintf(o->file, " @@%s\n", reset);
-       if (lc_a)
+       if (lc_a && !o->irreversible_delete)
                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
        if (lc_b)
                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
@@ -1981,7 +1984,11 @@ static void builtin_diff(const char *name_a,
                }
        }
 
-       if (!DIFF_OPT_TST(o, TEXT) &&
+       if (o->irreversible_delete && lbl[1][0] == '/') {
+               fprintf(o->file, "%s", header.buf);
+               strbuf_reset(&header);
+               goto free_ab_and_return;
+       } else if (!DIFF_OPT_TST(o, TEXT) &&
            ( (!textconv_one && diff_filespec_is_binary(one)) ||
              (!textconv_two && diff_filespec_is_binary(two)) )) {
                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
@@ -2001,8 +2008,7 @@ static void builtin_diff(const char *name_a,
                        fprintf(o->file, "%sBinary files %s and %s differ\n",
                                line_prefix, lbl[0], lbl[1]);
                o->found_changes = 1;
-       }
-       else {
+       } else {
                /* Crazy xdl interfaces.. */
                const char *diffopts = getenv("GIT_DIFF_OPTS");
                xpparam_t xpp;
@@ -3200,6 +3206,9 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                        return error("invalid argument to -M: %s", arg+2);
                options->detect_rename = DIFF_DETECT_RENAME;
        }
+       else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
+               options->irreversible_delete = 1;
+       }
        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
                 !strcmp(arg, "--find-copies")) {
                if (options->detect_rename == DIFF_DETECT_COPY)

diff --git a/diff.h b/diff.h
index b8dde8a750b17730f2e65da395700e5bd3ee2210..6fe1597785761b0e6961910214a129a2dde5197f 100644 (file)
--- a/diff.h
+++ b/diff.h
@@ -104,6 +104,7 @@ struct diff_options {
        int interhunkcontext;
        int break_opt;
        int detect_rename;
+       int irreversible_delete;
        int skip_stat_unmatch;
        int line_termination;
        int output_format;

diff --git a/t/t4022-diff-rewrite.sh b/t/t4022-diff-rewrite.sh
index 2a537a21e8e6793e6ffa2fe1522e30f877b209fe..c00a94b9ba4498e72a31856aac9cf653bbce8ba3 100755 (executable)
--- a/t/t4022-diff-rewrite.sh
+++ b/t/t4022-diff-rewrite.sh
@@ -11,7 +11,9 @@ test_expect_success setup '
        tr \
          "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" \
          "nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM" \
-         <"$TEST_DIRECTORY"/../COPYING >test
+         <"$TEST_DIRECTORY"/../COPYING >test &&
+       echo "to be deleted" >test2 &&
+       git add test2
 
 '
 
@@ -25,5 +27,44 @@ test_expect_success 'detect rewrite' '
 
 '
 
+cat >expect <<EOF
+diff --git a/test2 b/test2
+deleted file mode 100644
+index 4202011..0000000
+--- a/test2
++++ /dev/null
+@@ -1 +0,0 @@
+-to be deleted
+EOF
+test_expect_success 'show deletion diff without -D' '
+
+       rm test2 &&
+       git diff -- test2 >actual &&
+       test_cmp expect actual
+'
+
+cat >expect <<EOF
+diff --git a/test2 b/test2
+deleted file mode 100644
+index 4202011..0000000
+EOF
+test_expect_success 'suppress deletion diff with -D' '
+
+       git diff -D -- test2 >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'show deletion diff with -B' '
+
+       git diff -B -- test >actual &&
+       grep "Linus Torvalds" actual
+'
+
+test_expect_success 'suppress deletion diff with -B -D' '
+
+       git diff -B -D -- test >actual &&
+       grep -v "Linus Torvalds" actual
+'
+
 test_done