Fixing tabs in copy-paste

This resolves issues with copy-pasting tabs by including them in the
pasted string.

Selection of tabs is still inconsistent with what might be expected
based on other terminal emulators, however the behavior hasn't
regressed.

This fixes https://github.com/jwilm/alacritty/issues/219.

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Fix color issue in ncurses programs by updating terminfo pairs from 0x10000 to 0x7FFF
 - Fix panic after quitting Alacritty on macOS
+- Tabs are no longer replaced by spaces when copying them to the clipboard
 
 ## Version 0.2.4
 

Cargo.lock

@@ -716,7 +716,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1450,7 +1450,7 @@ dependencies = [
  "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2057,7 +2057,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2203,7 +2203,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "syn"
-version = "0.15.22"
+version = "0.15.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2218,7 +2218,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -3119,7 +3119,7 @@ dependencies = [
 "checksum static_assertions 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "389ce475f424f267dbed6479cbd8f126c5e1afb053b0acdaa019c74305fc65d1"
 "checksum stb_truetype 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "71a7d260b43b6129a22dc341be18a231044ca67a48b7e32625f380cc5ec9ad70"
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
-"checksum syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)" = "ae8b29eb5210bc5cf63ed6149cbf9adfc82ac0be023d8735c176ee74a2db4da7"
+"checksum syn 0.15.23 (registry+https://github.com/rust-lang/crates.io-index)" = "9545a6a093a3f0bd59adb472700acc08cad3776f860f16a897dfce8c88721cbc"
 "checksum synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "73687139bf99285483c96ac0add482c3776528beac1d97d444f6e91f203a2015"
 "checksum tempdir 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)" = "15f2b5fb00ccdf689e0149d1b1b3c03fead81c2b37735d812fa8bddbbf41b6d8"
 "checksum tempfile 3.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "7e91405c14320e5c79b3d148e1c86f40749a36e490642202a31689cb1a3452b2"

src/renderer/mod.rs

@@ -884,12 +884,17 @@ impl<'a> RenderApi<'a> {
             };
 
             // Don't render text of HIDDEN cells
-            let chars = if cell.flags.contains(cell::Flags::HIDDEN) {
+            let mut chars = if cell.flags.contains(cell::Flags::HIDDEN) {
                 [' '; cell::MAX_ZEROWIDTH_CHARS + 1]
             } else {
                 cell.chars
             };
 
+            // Render tabs as spaces in case the font doesn't support it
+            if chars[0] == '\t' {
+                chars[0] = ' ';
+            }
+
             let mut glyph_key = GlyphKey {
                 font_key,
                 size: glyph_cache.font_size,

src/term/cell.rs

@@ -114,7 +114,7 @@ impl Cell {
 
     #[inline]
     pub fn is_empty(&self) -> bool {
-        self.c == ' '
+        (self.c == ' ' || self.c == '\t')
             && self.extra[0] == ' '
             && self.bg == Color::Named(NamedColor::Background)
             && !self.flags.intersects(Flags::INVERSE | Flags::UNDERLINE)

src/term/mod.rs

@@ -763,7 +763,7 @@ pub struct Term {
     active_charset: CharsetIndex,
 
     /// Tabstops
-    tabs: Vec<bool>,
+    tabs: TabStops,
 
     /// Mode flags
     mode: TermMode,
@@ -915,9 +915,7 @@ impl Term {
         let alt = Grid::new(num_lines, num_cols, 0 /* scroll history */, Cell::default());
 
         let tabspaces = config.tabspaces();
-        let tabs = IndexRange::from(Column(0)..grid.num_cols())
+        let tabs = TabStops::new(grid.num_cols(), tabspaces);
-            .map(|i| (*i as usize) % tabspaces == 0)
-            .collect::<Vec<bool>>();
 
         let scroll_region = Line(0)..grid.num_lines();
 
@@ -1014,11 +1012,23 @@ impl Term {
         use std::ops::Range;
 
         trait Append : PushChar {
-            fn append(&mut self, grid: &Grid<Cell>, line: usize, cols: Range<Column>);
+            fn append(
+                &mut self,
+                grid: &Grid<Cell>,
+                tabs: &TabStops,
+                line: usize,
+                cols: Range<Column>,
+            );
         }
 
         impl Append for String {
-            fn append(&mut self, grid: &Grid<Cell>, mut line: usize, cols: Range<Column>) {
+            fn append(
+                &mut self,
+                grid: &Grid<Cell>,
+                tabs: &TabStops,
+                mut line: usize,
+                cols: Range<Column>
+            ) {
                 // Select until last line still within the buffer
                 line = min(line, grid.len() - 1);
 
@@ -1029,13 +1039,30 @@ impl Term {
                 if line_end.0 == 0 && cols.end >= grid.num_cols() - 1 {
                     self.push('\n');
                 } else if cols.start < line_end {
-                    for cell in &grid_line[cols.start..line_end] {
+                    let mut tab_mode = false;
+
+                    for col in IndexRange::from(cols.start..line_end) {
+                        let cell = grid_line[col];
+
+                        if tab_mode {
+                            // Skip over whitespace until next tab-stop once a tab was found
+                            if tabs[col] {
+                                tab_mode = false;
+                            } else if cell.c == ' ' {
+                                continue;
+                            }
+                        }
+
                         if !cell.flags.contains(cell::Flags::WIDE_CHAR_SPACER) {
                             self.push(cell.c);
                             for c in (&cell.chars()[1..]).iter().filter(|c| **c != ' ') {
                                 self.push(*c);
                             }
                         }
+
+                        if cell.c == '\t' {
+                            tab_mode = true;
+                        }
                     }
 
                     if cols.end >= grid.num_cols() - 1 {
@@ -1063,32 +1090,31 @@ impl Term {
         match line_count {
             // Selection within single line
             0 => {
-                res.append(&self.grid, start.line, start.col..end.col);
+                res.append(&self.grid, &self.tabs, start.line, start.col..end.col);
             },
 
             // Selection ends on line following start
             1 => {
                 // Ending line
-                res.append(&self.grid, end.line, end.col..max_col);
+                res.append(&self.grid, &self.tabs, end.line, end.col..max_col);
 
                 // Starting line
-                res.append(&self.grid, start.line, Column(0)..start.col);
+                res.append(&self.grid, &self.tabs, start.line, Column(0)..start.col);
 
             },
 
             // Multi line selection
             _ => {
                 // Ending line
-                res.append(&self.grid, end.line, end.col..max_col);
+                res.append(&self.grid, &self.tabs, end.line, end.col..max_col);
 
                 let middle_range = (start.line + 1)..(end.line);
                 for line in middle_range.rev() {
-                    res.append(&self.grid, line, Column(0)..max_col);
+                    res.append(&self.grid, &self.tabs, line, Column(0)..max_col);
                 }
 
                 // Starting line
-                res.append(&self.grid, start.line, Column(0)..start.col);
+                res.append(&self.grid, &self.tabs, start.line, Column(0)..start.col);
-
             }
         }
 
@@ -1232,9 +1258,7 @@ impl Term {
         self.cursor_save_alt.point.line = min(self.cursor_save_alt.point.line, num_lines - 1);
 
         // Recreate tabs list
-        self.tabs = IndexRange::from(Column(0)..self.grid.num_cols())
+        self.tabs = TabStops::new(self.grid.num_cols(), self.tabspaces);
-            .map(|i| (*i as usize) % self.tabspaces == 0)
-            .collect::<Vec<bool>>();
     }
 
     #[inline]
@@ -1553,23 +1577,26 @@ impl ansi::Handler for Term {
     fn put_tab(&mut self, mut count: i64) {
         trace!("put_tab: {}", count);
 
-        let mut col = self.cursor.point.col;
+        while self.cursor.point.col < self.grid.num_cols() && count != 0 {
-        while col < self.grid.num_cols() && count != 0 {
             count -= 1;
+
+            let cell = &mut self.grid[&self.cursor.point];
+            *cell = self.cursor.template;
+            cell.c = self.cursor.charsets[self.active_charset].map('\t');
+
             loop {
-                if (col + 1) == self.grid.num_cols() {
+                if (self.cursor.point.col + 1) == self.grid.num_cols() {
                     break;
                 }
 
-                col += 1;
+                self.cursor.point.col += 1;
 
-                if self.tabs[*col as usize] {
+                if self.tabs[self.cursor.point.col] {
                     break;
                 }
             }
         }
 
-        self.cursor.point.col = col;
         self.input_needs_wrap = false;
     }
 
@@ -1651,7 +1678,7 @@ impl ansi::Handler for Term {
     fn set_horizontal_tabstop(&mut self) {
         trace!("set_horizontal_tabstop");
         let column = self.cursor.point.col;
-        self.tabs[column.0] = true;
+        self.tabs[column] = true;
     }
 
     #[inline]
@@ -1731,7 +1758,7 @@ impl ansi::Handler for Term {
         for _ in 0..count {
             let mut col = self.cursor.point.col;
             for i in (0..(col.0)).rev() {
-                if self.tabs[i as usize] {
+                if self.tabs[index::Column(i)] {
                     col = index::Column(i);
                     break;
                 }
@@ -1874,15 +1901,10 @@ impl ansi::Handler for Term {
         match mode {
             ansi::TabulationClearMode::Current => {
                 let column = self.cursor.point.col;
-                self.tabs[column.0] = false;
+                self.tabs[column] = false;
             },
             ansi::TabulationClearMode::All => {
-                let len = self.tabs.len();
+                self.tabs.clear_all();
-                // Safe since false boolean is null, each item occupies only 1
-                // byte, and called on the length of the vec.
-                unsafe {
-                    ::std::ptr::write_bytes(self.tabs.as_mut_ptr(), 0, len);
-                }
             }
         }
     }
@@ -2068,6 +2090,40 @@ impl ansi::Handler for Term {
     }
 }
 
+struct TabStops {
+    tabs: Vec<bool>
+}
+
+impl TabStops {
+    fn new(num_cols: Column, tabspaces: usize) -> TabStops {
+        TabStops {
+            tabs: IndexRange::from(Column(0)..num_cols)
+                .map(|i| (*i as usize) % tabspaces == 0)
+                .collect::<Vec<bool>>()
+        }
+    }
+
+    fn clear_all(&mut self) {
+        unsafe {
+            ptr::write_bytes(self.tabs.as_mut_ptr(), 0, self.tabs.len());
+        }
+    }
+}
+
+impl Index<Column> for TabStops {
+    type Output = bool;
+
+    fn index(&self, index: Column) -> &bool {
+        &self.tabs[index.0]
+    }
+}
+
+impl IndexMut<Column> for TabStops {
+    fn index_mut(&mut self, index: Column) -> &mut bool {
+        self.tabs.index_mut(index.0)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use serde_json;

tests/ref/tab_rendering/alacritty.recording

@@ -1,6 +1,5 @@
-%                                                                               
 
]2;jwilm@jwilm-desk: ~/code/alacritty]1;..ode/alacritty
jwilm@jwilm-desk ➜  ~/code/alacritty  [?1h=[?2004h
+%                                                                                                                   
 

 UL  ~/…/tests/ref/tab_rendering  copy-tabs  [?2004hecho '\tb\na\tb\naa\tb\naaa\tb\naaaa\tb\naaaaa\tb\naaaaaa\tb\naaaaaaa\tb\naaaaaaaa\tb\naaaaaaaaa\tb\naaaaaaaaaa\tb'[?2004l
-bck-i-search: _target/debug/alacritty --ref-test --title alacritty-reftest
+	b
-bck-i-search: e_echo '\tb\na\tb\naa\tb\naaa\tb\naaaa\tb\naaaaa\tb\naaaaaa\tb\naaaaaaa\tb\naaaaaaaa\tb\naaaaaaaaa\tb\naaaaaaaaaa\tb'c_echh_hoo_echo '\tb\na\tb\naa\tb\naaa\tb\naaaa\tb\naaaaa\tb\naaaaaa\tb\naaaaaaa\tb\naaaaaaaa\tb\naaaaaaaaa\tb\naaaaaaaaaa\tb'
[?1l>[?2004l
]2;echo ]1;echo	b
 a	b
 aa	b
 aaa	b
@@ -11,4 +10,4 @@ aaaaaaa	b
 aaaaaaaa	b
 aaaaaaaaa	b
 aaaaaaaaaa	b
-%                                                                               
 
]2;jwilm@jwilm-desk: ~/code/alacritty]1;..ode/alacritty
jwilm@jwilm-desk ➜  ~/code/alacritty  [?1h=[?2004h
+%                                                                                                                   
 

 UL  ~/…/tests/ref/tab_rendering  copy-tabs  [?2004h

tests/ref/tab_rendering/size.json

@@ -1 +1 @@
-{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0,"padding_x":0.0,"padding_y":0.0}
+{"width":939.0,"height":1020.0,"cell_width":8.0,"cell_height":16.0,"padding_x":5.0,"padding_y":6.0,"dpr":1.0}

tests/ref/vttest_tab_clear_set/alacritty.recording

@@ -1,5 +1,5 @@
-%                                                                               
 

jwilm@sanctuary.local ➜  ~/code/alacritty  [?1h=[?2004hvvtvttteesvttest[?1l>[?2004l
+%                                                                                                                   
 

 UL  ~/…/tests/ref/vttest_tab_cle…  copy-tabs  [?2004hvttestvttest[?2004l
-[?1l[?3l[?4l[?5l[?6l[?7h[?8l[?40h[?45lVT100 test program, version 2.7 (20140305)Choose test type:
+[?1l[?3l[?4l[?5l[?6l[?7h[?8l[?40h[?45lVT100 test program, version 2.7 (20180911)Line speed 38400bd Choose test type:
 
           0. Exit
           1. Test of cursor movements

tests/ref/vttest_tab_clear_set/size.json

@@ -1 +1 @@
-{"width":1124.0,"height":676.0,"cell_width":14.0,"cell_height":28.0,"padding_x":0.0,"padding_y":0.0}
+{"width":939.0,"height":503.0,"cell_width":8.0,"cell_height":16.0,"padding_x":5.0,"padding_y":3.0,"dpr":1.0}