Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 158 insertions, 0 deletions

diff --git a/vendor/clap/src/output/textwrap/core.rs b/vendor/clap/src/output/textwrap/core.rs
new file mode 100644
index 000000000..b890c6c7b
--- /dev/null
+++ b/vendor/clap/src/output/textwrap/core.rs
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+/// Compute the display width of `text`
+///
+/// # Examples
+///
+/// **Note:** When the `unicode` Cargo feature is disabled, all characters are presumed to take up
+/// 1 width.  With the feature enabled, function will correctly deal with [combining characters] in
+/// their decomposed form (see [Unicode equivalence]).
+///
+/// An example of a decomposed character is “é”, which can be decomposed into: “e” followed by a
+/// combining acute accent: “◌́”.  Without the `unicode` Cargo feature, every `char` has a width of
+/// 1. This includes the combining accent:
+///
+/// ## Emojis and CJK Characters
+///
+/// Characters such as emojis and [CJK characters] used in the
+/// Chinese, Japanese, and Korean languages are seen as double-width,
+/// even if the `unicode-width` feature is disabled:
+///
+/// # Limitations
+///
+/// The displayed width of a string cannot always be computed from the
+/// string alone. This is because the width depends on the rendering
+/// engine used. This is particularly visible with [emoji modifier
+/// sequences] where a base emoji is modified with, e.g., skin tone or
+/// hair color modifiers. It is up to the rendering engine to detect
+/// this and to produce a suitable emoji.
+///
+/// A simple example is “❤️”, which consists of “❤” (U+2764: Black
+/// Heart Symbol) followed by U+FE0F (Variation Selector-16). By
+/// itself, “❤” is a black heart, but if you follow it with the
+/// variant selector, you may get a wider red heart.
+///
+/// A more complex example would be “👨‍🦰” which should depict a man
+/// with red hair. Here the computed width is too large — and the
+/// width differs depending on the use of the `unicode-width` feature:
+///
+/// This happens because the grapheme consists of three code points:
+/// “👨” (U+1F468: Man), Zero Width Joiner (U+200D), and “🦰”
+/// (U+1F9B0: Red Hair). You can see them above in the test. With
+/// `unicode-width` enabled, the ZWJ is correctly seen as having zero
+/// width, without it is counted as a double-width character.
+///
+/// ## Terminal Support
+///
+/// Modern browsers typically do a great job at combining characters
+/// as shown above, but terminals often struggle more. As an example,
+/// Gnome Terminal version 3.38.1, shows “❤️” as a big red heart, but
+/// shows "👨‍🦰" as “👨🦰”.
+///
+/// [combining characters]: https://en.wikipedia.org/wiki/Combining_character
+/// [Unicode equivalence]: https://en.wikipedia.org/wiki/Unicode_equivalence
+/// [CJK characters]: https://en.wikipedia.org/wiki/CJK_characters
+/// [emoji modifier sequences]: https://unicode.org/emoji/charts/full-emoji-modifiers.html
+#[inline(never)]
+pub(crate) fn display_width(text: &str) -> usize {
+    let mut width = 0;
+
+    let mut control_sequence = false;
+    let control_terminate: char = 'm';
+
+    for ch in text.chars() {
+        if ch.is_ascii_control() {
+            control_sequence = true;
+        } else if control_sequence && ch == control_terminate {
+            control_sequence = false;
+            continue;
+        }
+
+        if !control_sequence {
+            width += ch_width(ch);
+        }
+    }
+    width
+}
+
+#[cfg(feature = "unicode")]
+fn ch_width(ch: char) -> usize {
+    unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0)
+}
+
+#[cfg(not(feature = "unicode"))]
+fn ch_width(_: char) -> usize {
+    1
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[cfg(feature = "unicode")]
+    use unicode_width::UnicodeWidthChar;
+
+    #[test]
+    fn emojis_have_correct_width() {
+        use unic_emoji_char::is_emoji;
+
+        // Emojis in the Basic Latin (ASCII) and Latin-1 Supplement
+        // blocks all have a width of 1 column. This includes
+        // characters such as '#' and '©'.
+        for ch in '\u{1}'..'\u{FF}' {
+            if is_emoji(ch) {
+                let desc = format!("{:?} U+{:04X}", ch, ch as u32);
+
+                #[cfg(feature = "unicode")]
+                assert_eq!(ch.width().unwrap(), 1, "char: {}", desc);
+
+                #[cfg(not(feature = "unicode"))]
+                assert_eq!(ch_width(ch), 1, "char: {}", desc);
+            }
+        }
+
+        // Emojis in the remaining blocks of the Basic Multilingual
+        // Plane (BMP), in the Supplementary Multilingual Plane (SMP),
+        // and in the Supplementary Ideographic Plane (SIP), are all 1
+        // or 2 columns wide when unicode-width is used, and always 2
+        // columns wide otherwise. This includes all of our favorite
+        // emojis such as 😊.
+        for ch in '\u{FF}'..'\u{2FFFF}' {
+            if is_emoji(ch) {
+                let desc = format!("{:?} U+{:04X}", ch, ch as u32);
+
+                #[cfg(feature = "unicode")]
+                assert!(ch.width().unwrap() <= 2, "char: {}", desc);
+
+                #[cfg(not(feature = "unicode"))]
+                assert_eq!(ch_width(ch), 1, "char: {}", desc);
+            }
+        }
+
+        // The remaining planes contain almost no assigned code points
+        // and thus also no emojis.
+    }
+
+    #[test]
+    #[cfg(feature = "unicode")]
+    fn display_width_works() {
+        assert_eq!("Café Plain".len(), 11); // “é” is two bytes
+        assert_eq!(display_width("Café Plain"), 10);
+    }
+
+    #[test]
+    #[cfg(feature = "unicode")]
+    fn display_width_narrow_emojis() {
+        assert_eq!(display_width("⁉"), 1);
+    }
+
+    #[test]
+    #[cfg(feature = "unicode")]
+    fn display_width_narrow_emojis_variant_selector() {
+        assert_eq!(display_width("⁉\u{fe0f}"), 1);
+    }
+
+    #[test]
+    #[cfg(feature = "unicode")]
+    fn display_width_emojis() {
+        assert_eq!(display_width("😂😭🥺🤣✨😍🙏🥰😊🔥"), 20);
+    }
+}