Use checked `str` slices in `Rgba::TryFrom<str>` (#12097)

bbb651 and Kirill Bulatov created 2 years ago

Release Notes:

- N/A

---------

Co-authored-by: Kirill Bulatov <[e-mail]>

Change summary

crates/gpui/src/color.rs | 68 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 59 insertions(+), 9 deletions(-)

Detailed changes

crates/gpui/src/color.rs

@@ -1,4 +1,4 @@
-use anyhow::bail;
+use anyhow::{bail, Context};
 use serde::de::{self, Deserialize, Deserializer, Visitor};
 use std::fmt;
 
@@ -126,6 +126,7 @@ impl TryFrom<&'_ str> for Rgba {
         const RRGGBBAA: usize = "rrggbbaa".len();
 
         const EXPECTED_FORMATS: &str = "Expected #rgb, #rgba, #rrggbb, or #rrggbbaa";
+        const INVALID_UNICODE: &str = "invalid unicode characters in color";
 
         let Some(("", hex)) = value.trim().split_once('#') else {
             bail!("invalid RGBA hex color: '{value}'. {EXPECTED_FORMATS}");
@@ -133,11 +134,31 @@ impl TryFrom<&'_ str> for Rgba {
 
         let (r, g, b, a) = match hex.len() {
             RGB | RGBA => {
-                let r = u8::from_str_radix(&hex[0..1], 16)?;
-                let g = u8::from_str_radix(&hex[1..2], 16)?;
-                let b = u8::from_str_radix(&hex[2..3], 16)?;
+                let r = u8::from_str_radix(
+                    hex.get(0..1).with_context(|| {
+                        format!("{INVALID_UNICODE}: r component of #rgb/#rgba for value: '{value}'")
+                    })?,
+                    16,
+                )?;
+                let g = u8::from_str_radix(
+                    hex.get(1..2).with_context(|| {
+                        format!("{INVALID_UNICODE}: g component of #rgb/#rgba for value: '{value}'")
+                    })?,
+                    16,
+                )?;
+                let b = u8::from_str_radix(
+                    hex.get(2..3).with_context(|| {
+                        format!("{INVALID_UNICODE}: b component of #rgb/#rgba for value: '{value}'")
+                    })?,
+                    16,
+                )?;
                 let a = if hex.len() == RGBA {
-                    u8::from_str_radix(&hex[3..4], 16)?
+                    u8::from_str_radix(
+                        hex.get(3..4).with_context(|| {
+                            format!("{INVALID_UNICODE}: a component of #rgba for value: '{value}'")
+                        })?,
+                        16,
+                    )?
                 } else {
                     0xf
                 };
@@ -151,11 +172,40 @@ impl TryFrom<&'_ str> for Rgba {
                 (duplicate(r), duplicate(g), duplicate(b), duplicate(a))
             }
             RRGGBB | RRGGBBAA => {
-                let r = u8::from_str_radix(&hex[0..2], 16)?;
-                let g = u8::from_str_radix(&hex[2..4], 16)?;
-                let b = u8::from_str_radix(&hex[4..6], 16)?;
+                let r = u8::from_str_radix(
+                    hex.get(0..2).with_context(|| {
+                        format!(
+                            "{}: r component of #rrggbb/#rrggbbaa for value: '{}'",
+                            INVALID_UNICODE, value
+                        )
+                    })?,
+                    16,
+                )?;
+                let g = u8::from_str_radix(
+                    hex.get(2..4).with_context(|| {
+                        format!(
+                            "{INVALID_UNICODE}: g component of #rrggbb/#rrggbbaa for value: '{value}'"
+                        )
+                    })?,
+                    16,
+                )?;
+                let b = u8::from_str_radix(
+                    hex.get(4..6).with_context(|| {
+                        format!(
+                            "{INVALID_UNICODE}: b component of #rrggbb/#rrggbbaa for value: '{value}'"
+                        )
+                    })?,
+                    16,
+                )?;
                 let a = if hex.len() == RRGGBBAA {
-                    u8::from_str_radix(&hex[6..8], 16)?
+                    u8::from_str_radix(
+                        hex.get(6..8).with_context(|| {
+                            format!(
+                                "{INVALID_UNICODE}: a component of #rrggbbaa for value: '{value}'"
+                            )
+                        })?,
+                        16,
+                    )?
                 } else {
                     0xff
                 };