Fix ssa parsing error if style contains leading or trailing whitespaces

Author: bytedream

src/ssa.rs

@@ -1006,7 +1006,7 @@ mod parse {
         list: &'a Vec<&str>,
         header_line: usize,
         current_line: usize,
-    ) -> Result<&'a &'a str> {
+    ) -> Result<&'a str> {
         let pos = headers
             .iter()
             .position(|h| {
@@ -1019,7 +1019,7 @@ mod parse {
                 kind: SSAErrorKind::MissingHeader(name.to_string()),
             })?;
 
-        list.get(pos).ok_or(Error {
+        list.get(pos).map(|l| l.trim()).ok_or(Error {
             line: current_line,
             kind: SSAErrorKind::Parse(format!("no value for header '{}'", name)),
         })

tests/ssa.rs

@@ -837,6 +837,18 @@ Style: Default,Arial,25.5,&H00FFFFFF,&H00000000,{color},&H00000000,-1,0,0,0,120,
     }
 }
 
+#[test]
+fn styles_whitespace() {
+    let ssa = r#"[Script Info]
+
+[V4+ Styles]
+Format: Name,Fontname,Fontsize,PrimaryColour,SecondaryColour,OutlineColour,BackColour,Bold,Italic,Underline,StrikeOut,ScaleX,ScaleY,Spacing,Angle,BorderStyle,Outline,Shadow,Alignment,MarginL,MarginR,MarginV,Encoding
+Style: Default, Arial,   25.5,&H00FFFFFF,&H00000000, &H00000000 ,&H00000000,-1 ,0,   0      ,0,120,120,0,0,1,1,1,2,0000,0000,0030,0
+"#;
+
+    let _ = SSA::parse(ssa).unwrap();
+}
+
 #[test]
 fn events_missing_header() {
     let ssa = r#"[Script Info]