Merging upstream version 1.75.0+dfsg1.

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

1 files changed, 38 insertions, 0 deletions

diff --git a/vendor/gix-features-0.35.0/src/decode.rs b/vendor/gix-features-0.35.0/src/decode.rs
new file mode 100644
index 000000000..0df38710d
--- /dev/null
+++ b/vendor/gix-features-0.35.0/src/decode.rs
@@ -0,0 +1,38 @@
+use std::io::Read;
+
+/// Decode variable int numbers from a `Read` implementation.
+///
+/// Note: currently overflow checks are only done in debug mode.
+#[inline]
+pub fn leb64_from_read(mut r: impl Read) -> Result<(u64, usize), std::io::Error> {
+    let mut b = [0u8; 1];
+    let mut i = 0;
+    r.read_exact(&mut b)?;
+    i += 1;
+    let mut value = b[0] as u64 & 0x7f;
+    while b[0] & 0x80 != 0 {
+        r.read_exact(&mut b)?;
+        i += 1;
+        debug_assert!(i <= 10, "Would overflow value at 11th iteration");
+        value += 1;
+        value = (value << 7) + (b[0] as u64 & 0x7f)
+    }
+    Ok((value, i))
+}
+
+/// Decode variable int numbers.
+#[inline]
+pub fn leb64(d: &[u8]) -> (u64, usize) {
+    let mut i = 0;
+    let mut c = d[i];
+    i += 1;
+    let mut value = c as u64 & 0x7f;
+    while c & 0x80 != 0 {
+        c = d[i];
+        i += 1;
+        debug_assert!(i <= 10, "Would overflow value at 11th iteration");
+        value += 1;
+        value = (value << 7) + (c as u64 & 0x7f)
+    }
+    (value, i)
+}