diff.c: decouple white space treatment from move detection algorithm
In the original implementation of the move detection logic the choice for ignoring white space changes is the same for the move detection as it is for the regular diff. Some cases came up where different treatment would have been nice. Allow the user to specify that white space should be ignored differently during detection of moved lines than during generation of added and removed lines. This is done by providing analogs to the --ignore-space-at-eol, -b, and -w options by introducing the option --color-moved-ws=<modes> with the modes named "ignore-space-at-eol", "ignore-space-change" and "ignore-all-space", which is used only during the move detection phase. As we change the default, we'll adjust the tests. For now we do not infer any options to treat white spaces in the move detection from the generic white space options given to diff. This can be tuned later to reasonable default. As we plan on adding more white space related options in a later patch, that interferes with the current white space options, use a flag field and clamp it down to XDF_WHITESPACE_FLAGS, as that (a) allows to easily check at parse time if we give invalid combinations and (b) can reuse parts of this patch. By having the white space treatment in its own option, we'll also make it easier for a later patch to have an config option for spaces in the move detection. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stefan Beller committed
Jul 16, 2018 at 16:05 UTC
b3095712f9d81572c3658d579e50db907b72f46d
4 files changed
+113
-6
Documentation/diff-options.txt
+17
@@ -292,6 +292,23 @@ dimmed_zebra::
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blocks are considered interesting, the rest is uninteresting.
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--
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+--color-moved-ws=<modes>::
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+ This configures how white spaces are ignored when performing the
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+ move detection for `--color-moved`. These modes can be given
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+ as a comma separated list:
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++
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+--
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+ignore-space-at-eol::
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+ Ignore changes in whitespace at EOL.
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+ignore-space-change::
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+ Ignore changes in amount of whitespace. This ignores whitespace
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+ at line end, and considers all other sequences of one or
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+ more whitespace characters to be equivalent.
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+ignore-all-space::
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+ Ignore whitespace when comparing lines. This ignores differences
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+ even if one line has whitespace where the other line has none.
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+--
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+
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--word-diff[=<mode>]::
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Show a word diff, using the <mode> to delimit changed words.
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By default, words are delimited by whitespace; see
diff.c
+37
-2
@@ -283,6 +283,36 @@ static int parse_color_moved(const char *arg)
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return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed_zebra', 'plain'"));
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}
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+static int parse_color_moved_ws(const char *arg)
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+{
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+ int ret = 0;
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+ struct string_list l = STRING_LIST_INIT_DUP;
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+ struct string_list_item *i;
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+
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+ string_list_split(&l, arg, ',', -1);
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+
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+ for_each_string_list_item(i, &l) {
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+ struct strbuf sb = STRBUF_INIT;
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+ strbuf_addstr(&sb, i->string);
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+ strbuf_trim(&sb);
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+
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+ if (!strcmp(sb.buf, "ignore-space-change"))
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+ ret |= XDF_IGNORE_WHITESPACE_CHANGE;
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+ else if (!strcmp(sb.buf, "ignore-space-at-eol"))
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+ ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
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+ else if (!strcmp(sb.buf, "ignore-all-space"))
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+ ret |= XDF_IGNORE_WHITESPACE;
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+ else
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+ error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
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+
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+ strbuf_release(&sb);
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+ }
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+
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+ string_list_clear(&l, 0);
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+
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+ return ret;
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+}
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+
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int git_diff_ui_config(const char *var, const char *value, void *cb)
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{
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if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
@@ -717,10 +747,12 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
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const struct diff_options *diffopt = hashmap_cmp_fn_data;
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const struct moved_entry *a = entry;
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const struct moved_entry *b = entry_or_key;
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+ unsigned flags = diffopt->color_moved_ws_handling
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+ & XDF_WHITESPACE_FLAGS;
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return !xdiff_compare_lines(a->es->line, a->es->len,
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b->es->line, b->es->len,
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- diffopt->xdl_opts);
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+ flags);
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}
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static struct moved_entry *prepare_entry(struct diff_options *o,
@@ -728,8 +760,9 @@ static struct moved_entry *prepare_entry(struct diff_options *o,
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{
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struct moved_entry *ret = xmalloc(sizeof(*ret));
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struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
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+ unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
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- ret->ent.hash = xdiff_hash_string(l->line, l->len, o->xdl_opts);
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+ ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
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ret->es = l;
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ret->next_line = NULL;
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@@ -4710,6 +4743,8 @@ int diff_opt_parse(struct diff_options *options,
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if (cm < 0)
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die("bad --color-moved argument: %s", arg);
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options->color_moved = cm;
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+ } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
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+ options->color_moved_ws_handling = parse_color_moved_ws(arg);
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} else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
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options->use_color = 1;
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options->word_diff = DIFF_WORDS_COLOR;
diff.h
+1
@@ -214,6 +214,7 @@ struct diff_options {
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} color_moved;
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#define COLOR_MOVED_DEFAULT COLOR_MOVED_ZEBRA
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#define COLOR_MOVED_MIN_ALNUM_COUNT 20
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+ int color_moved_ws_handling;
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};
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void diff_emit_submodule_del(struct diff_options *o, const char *line);
t/t4015-diff-whitespace.sh
+58
-4
@@ -1460,7 +1460,8 @@ test_expect_success 'move detection ignoring whitespace ' '
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EOF
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test_cmp expected actual &&
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- git diff HEAD --no-renames -w --color-moved --color >actual.raw &&
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+ git diff HEAD --no-renames --color-moved --color \
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+ --color-moved-ws=ignore-all-space >actual.raw &&
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grep -v "index" actual.raw | test_decode_color >actual &&
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cat <<-\EOF >expected &&
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<BOLD>diff --git a/lines.txt b/lines.txt<RESET>
@@ -1522,7 +1523,8 @@ test_expect_success 'move detection ignoring whitespace changes' '
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EOF
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test_cmp expected actual &&
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- git diff HEAD --no-renames -b --color-moved --color >actual.raw &&
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+ git diff HEAD --no-renames --color-moved --color \
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+ --color-moved-ws=ignore-space-change >actual.raw &&
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grep -v "index" actual.raw | test_decode_color >actual &&
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cat <<-\EOF >expected &&
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<BOLD>diff --git a/lines.txt b/lines.txt<RESET>
@@ -1587,7 +1589,8 @@ test_expect_success 'move detection ignoring whitespace at eol' '
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EOF
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test_cmp expected actual &&
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- git diff HEAD --no-renames --ignore-space-at-eol --color-moved --color >actual.raw &&
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+ git diff HEAD --no-renames --color-moved --color \
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+ --color-moved-ws=ignore-space-at-eol >actual.raw &&
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grep -v "index" actual.raw | test_decode_color >actual &&
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cat <<-\EOF >expected &&
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<BOLD>diff --git a/lines.txt b/lines.txt<RESET>
@@ -1757,7 +1760,58 @@ test_expect_success 'move detection with submodules' '
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# nor did we mess with it another way
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git diff --submodule=diff --color | test_decode_color >expect &&
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- test_cmp expect decoded_actual
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+ test_cmp expect decoded_actual &&
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+ rm -rf bananas &&
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+ git submodule deinit bananas
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+'
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+
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+test_expect_success 'only move detection ignores white spaces' '
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+ git reset --hard &&
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+ q_to_tab <<-\EOF >text.txt &&
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+ a long line to exceed per-line minimum
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+ another long line to exceed per-line minimum
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+ original file
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+ EOF
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+ git add text.txt &&
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+ git commit -m "add text" &&
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+ q_to_tab <<-\EOF >text.txt &&
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+ Qa long line to exceed per-line minimum
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+ Qanother long line to exceed per-line minimum
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+ new file
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+ EOF
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+
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+ # Make sure we get a different diff using -w
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+ git diff --color --color-moved -w >actual.raw &&
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+ grep -v "index" actual.raw | test_decode_color >actual &&
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+ q_to_tab <<-\EOF >expected &&
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+ <BOLD>diff --git a/text.txt b/text.txt<RESET>
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+ <BOLD>--- a/text.txt<RESET>
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+ <BOLD>+++ b/text.txt<RESET>
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+ <CYAN>@@ -1,3 +1,3 @@<RESET>
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+ Qa long line to exceed per-line minimum<RESET>
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+ Qanother long line to exceed per-line minimum<RESET>
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+ <RED>-original file<RESET>
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+ <GREEN>+<RESET><GREEN>new file<RESET>
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+ EOF
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+ test_cmp expected actual &&
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+
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+ # And now ignoring white space only in the move detection
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+ git diff --color --color-moved \
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+ --color-moved-ws=ignore-all-space,ignore-space-change,ignore-space-at-eol >actual.raw &&
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+ grep -v "index" actual.raw | test_decode_color >actual &&
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+ q_to_tab <<-\EOF >expected &&
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+ <BOLD>diff --git a/text.txt b/text.txt<RESET>
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+ <BOLD>--- a/text.txt<RESET>
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+ <BOLD>+++ b/text.txt<RESET>
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+ <CYAN>@@ -1,3 +1,3 @@<RESET>
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+ <BOLD;MAGENTA>-a long line to exceed per-line minimum<RESET>
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+ <BOLD;MAGENTA>-another long line to exceed per-line minimum<RESET>
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+ <RED>-original file<RESET>
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+ <BOLD;YELLOW>+<RESET>Q<BOLD;YELLOW>a long line to exceed per-line minimum<RESET>
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+ <BOLD;YELLOW>+<RESET>Q<BOLD;YELLOW>another long line to exceed per-line minimum<RESET>
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+ <GREEN>+<RESET><GREEN>new file<RESET>
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+ EOF
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+ test_cmp expected actual
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'
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test_done