fix: Cap span expansion at u16::MAX (65535) line range

Prevents excessive iteration from malformed mapping files where the
original line range could be extremely large (up to u32::MAX).  The JVM
bytecode maximum line number is 65535, so any span beyond that is
invalid and falls through to single-line handling.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: romtsn

src/cache/mod.rs

@@ -1002,9 +1002,12 @@ fn iterate_with_lines<'a>(
                 );
             }
             // Span expansion: if the original range spans multiple lines,
-            // emit one frame per original line.
+            // emit one frame per original line.  Cap the span at
+            // u16::MAX (65535), the JVM bytecode maximum line number.
             if member.original_endline != u32::MAX
                 && member.original_endline > member.original_startline().unwrap_or(0)
+                && (member.original_endline - member.original_startline().unwrap_or(0))
+                    <= u16::MAX as u32
             {
                 let first_line = member.original_startline().unwrap_or(0) as usize;
                 let last_line = member.original_endline as usize;

src/mapper.rs

@@ -698,10 +698,11 @@ impl<'s> ProguardMapper<'s> {
                         continue;
                     }
                     // Span expansion: if the original range spans multiple lines,
-                    // emit one frame per original line.
+                    // emit one frame per original line.  Cap the span at
+                    // u16::MAX (65535), the JVM bytecode maximum line number.
                     if let Some(oe) = member.original_endline {
                         let os = member.original_startline.unwrap_or(0);
-                        if oe > os {
+                        if oe > os && (oe - os) <= u16::MAX as usize {
                             for line in os..=oe {
                                 collected.frames.push(map_member_without_lines(
                                     &frame,