From e101610416400534e2da70ee25d72ad348cf33f6 Mon Sep 17 00:00:00 2001
From: LagoLunatic <LagoLunatic@users.noreply.github.com>
Date: Mon, 31 Mar 2025 00:00:06 -0400
Subject: [PATCH] ARM: Fix subtract with overflow error when no mapping symbol
 at address 0 (#183)

---
 objdiff-core/src/arch/arm.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/objdiff-core/src/arch/arm.rs b/objdiff-core/src/arch/arm.rs
index c8d66a7..92ef577 100644
--- a/objdiff-core/src/arch/arm.rs
+++ b/objdiff-core/src/arch/arm.rs
@@ -199,7 +199,7 @@ impl Arch for ArchArm {
             .unwrap_or(&fallback_mappings);
         let first_mapping_idx = mapping_symbols
             .binary_search_by_key(&start_addr, |x| x.address)
-            .unwrap_or_else(|idx| idx - 1);
+            .unwrap_or_else(|idx| idx.saturating_sub(1));
         let mut mode = mapping_symbols[first_mapping_idx].mapping;
 
         let mut mappings_iter = mapping_symbols