hlssink3/hlscmafsink: Add test for validating non-overlapping byte range

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/2439>

net/hlssink3/tests/common/mod.rs

@@ -12,6 +12,12 @@ pub struct ByteRange {
     offset: u64,
 }
 
+impl ByteRange {
+    fn end(&self) -> u64 {
+        self.offset + self.length
+    }
+}
+
 pub fn get_byte_ranges(s: &gst::StructureRef) -> Vec<ByteRange> {
     let mut ranges = Vec::new();
 
@@ -43,3 +49,23 @@ pub fn validate_byterange_sequence(ranges: &[ByteRange]) -> bool {
         next.offset == current.offset + current.length
     })
 }
+
+fn ranges_overlap(a: &ByteRange, b: &ByteRange) -> bool {
+    a.offset < b.end() && b.offset < a.end()
+}
+
+pub fn all_ranges_non_overlapping(ranges: &[ByteRange]) -> bool {
+    if ranges.len() <= 1 {
+        return true; // 0 or 1 range cannot overlap
+    }
+
+    for i in 0..ranges.len() {
+        for j in (i + 1)..ranges.len() {
+            if ranges_overlap(&ranges[i], &ranges[j]) {
+                return false;
+            }
+        }
+    }
+
+    true
+}

net/hlssink3/tests/hlscmafsink.rs

@@ -205,6 +205,7 @@ fn test_hlscmafsink_video_with_single_media_file() -> Result<(), ()> {
     // byte range can differ from each run and hence we do not validate
     // the entire playlist.
     assert!(validate_byterange_sequence(&byte_ranges));
+    assert!(all_ranges_non_overlapping(&byte_ranges));
 
     let expected_messages = {
         use self::HlsSinkEvent::*;

net/hlssink3/tests/hlssink3.rs

@@ -14,7 +14,7 @@ use std::sync::LazyLock;
 use std::sync::{mpsc, Arc, Mutex};
 
 mod common;
-use crate::common::{get_byte_ranges, validate_byterange_sequence, ByteRange};
+use crate::common::*;
 
 static CAT: LazyLock<gst::DebugCategory> = LazyLock::new(|| {
     gst::DebugCategory::new(
@@ -657,6 +657,7 @@ fn test_hlssink3_video_with_single_media_file() -> Result<(), ()> {
     // range can differ from each run and hence we do not validate
     // the entire playlist.
     assert!(validate_byterange_sequence(&byte_ranges));
+    assert!(all_ranges_non_overlapping(&byte_ranges));
 
     let expected_messages = {
         use self::HlsSinkEvent::*;