Allow to hide +/- signs in the diff view

Use `:toggle diff-indicator` to show or hide the +/- signs in the diff view.

Closes #855, closes #901

Author: koutcher

doc/tigrc.5.adoc

@@ -290,6 +290,10 @@ The following variables can be set:
 	regions are governed by `color diff-add-highlight` and
 	`color diff-del-highlight`.
 
+'diff-indicator' (bool)::
+
+	Show +/- signs in the diff view. On by default.
+
 'ignore-space' (mixed) [no|all|some|at-eol|<bool>]::
 
 	Ignore space changes in diff view. By default no space changes are
@@ -301,7 +305,7 @@ The following variables can be set:
 	the *status-update* and *status-revert* may fail when updating or
 	reverting chunks containing lines with space changes. Similarly,
 	*stage-update-line* may fail when updating a line adjacent to a line
-	with space changes
+	with space changes.
 
 'commit-order' (enum) [auto|default|topo|date|author-date|reverse]::
 

include/tig/diff.h

@@ -24,6 +24,8 @@ struct diff_state {
 	bool combined_diff;
 	bool adding_describe_ref;
 	bool highlight;
+	bool stage;
+	unsigned int parents;
 	const char *file;
 	unsigned int lineno;
 	struct position pos;

include/tig/options.h

@@ -36,6 +36,7 @@ typedef struct view_column *view_settings;
 	_(blob_view,			view_settings,		VIEW_NO_FLAGS) \
 	_(commit_order,			enum commit_order,	VIEW_LOG_LIKE) \
 	_(diff_context,			int,			VIEW_DIFF_LIKE) \
+	_(diff_indicator,		bool,			VIEW_DIFF_LIKE) \
 	_(diff_noprefix,		bool,			VIEW_NO_FLAGS) \
 	_(diff_options,			const char **,		VIEW_DIFF_LIKE) \
 	_(diff_highlight,		const char *,		VIEW_DIFF_LIKE) \

include/tig/parse.h

@@ -63,10 +63,10 @@ size_t parse_size(const char *text);
 const char *get_path(const char *path);
 struct ident *get_author(const char *name, const char *email);
 
-static inline int
+static inline unsigned int
 chunk_header_marker_length(const char *data)
 {
-	int len = 0;
+	unsigned int len = 0;
 	for (; *data == '@'; data++)
 		len++;
 	return len;

src/diff.c

@@ -347,7 +347,7 @@ diff_common_read(struct view *view, const char *data, struct diff_state *state)
 		state->reading_diff_chunk = false;
 
 	} else if (type == LINE_DIFF_CHUNK) {
-		const int len = chunk_header_marker_length(data);
+		const unsigned int len = chunk_header_marker_length(data);
 		const char *context = strstr(data + len, "@@");
 		struct line *line =
 			context ? add_line_text_at(view, view->lines, data, LINE_DIFF_CHUNK, len)
@@ -362,20 +362,26 @@ diff_common_read(struct view *view, const char *data, struct diff_state *state)
 		box->cell[1].length = strlen(context + len);
 		box->cell[box->cells++].type = LINE_DIFF_STAT;
 		state->combined_diff = (len > 2);
+		state->parents = len - 1;
 		state->reading_diff_chunk = true;
 		return true;
 
 	} else if (type == LINE_COMMIT) {
 		state->reading_diff_chunk = false;
 
-	} else if (state->highlight && strchr(data, 0x1b)) {
-		return diff_common_highlight(view, data, type);
+	}
 
-	} else if (opt_word_diff && state->reading_diff_chunk &&
-		   /* combined diff format is not using word diff */
-		   !state->combined_diff) {
+	if (opt_word_diff && state->reading_diff_chunk &&
+	    /* combined diff format is not using word diff */
+	    !state->combined_diff)
 		return diff_common_read_diff_wdiff(view, data);
-	}
+
+	if (!opt_diff_indicator && state->reading_diff_chunk &&
+	    !state->stage)
+		data += state->parents;
+
+	if (state->highlight && strchr(data, 0x1b))
+		return diff_common_highlight(view, data, type);
 
 	return pager_common_read(view, data, type, NULL);
 }

src/stage.c

@@ -769,18 +769,17 @@ stage_open(struct view *view, enum open_flags flags)
 	}
 
 	if (!status_stage_info(view->ref, stage_line_type, &stage_status))
-		return error("Failed to open staged view");
+		return error("Failed to open stage view");
+
+	state->diff.stage = true;
 
 	if (stage_line_type != LINE_STAT_UNTRACKED)
 		diff_save_line(view, &state->diff, flags);
 
 	view->vid[0] = 0;
 	code = begin_update(view, repo.exec_dir, argv, flags | OPEN_WITH_STDERR);
-	if (code == SUCCESS && stage_line_type != LINE_STAT_UNTRACKED) {
-		struct stage_state *state = view->private;
-
+	if (code == SUCCESS && stage_line_type != LINE_STAT_UNTRACKED)
 		return diff_init_highlight(view, &state->diff);
-	}
 
 	return code;
 }

tigrc

@@ -122,8 +122,9 @@ set show-notes			= yes		# When non-bool passed as `--show-notes=...` (diff)
 #set diff-context		= 3		# Number of lines to show around diff changes (diff)
 #set word-diff			= yes		# Show a word diff? (diff)
 #set diff-options		= -C		# User-defined options for `tig show` (git-diff)
-#set diff-highlight		= true		# String (or bool): Path to diff-highlight script,
+#set diff-highlight		= yes		# String (or bool): Path to diff-highlight script,
 						#                   defaults to `diff-highlight`.
+set diff-indicator		= yes		# Show diff +/- signs?
 #set blame-options		= -C -C -C	# User-defined options for `tig blame` (git-blame)
 set log-options			= --cc --stat	# User-defined options for `tig log` (git-log)
 #set main-options		= -n 1000	# User-defined options for `tig` (git-log)
@@ -326,6 +327,7 @@ bind generic	$	:toggle commit-title-overflow
 						# Toggle display of file in untracked directories
 # bind generic	???	:toggle vertical-split	# Toggle vertical split
 # bind generic	???	:toggle word-diff	# Toggle word diff
+# bind generic	???	:toggle diff-indicator	# Toggle display of diff +/- signs
 bind generic	%	:toggle file-filter	# Toggle filtering by pathspecs in file-args
 bind generic	^	:toggle rev-filter	# Toggle filtering by revisions in rev-args