From 19929cf76924d1686a55b2c1befef66efabd42f2 Mon Sep 17 00:00:00 2001
From: Kuba Groblewski <kkgroblewski@gmail.com>
Date: Sat, 22 Jun 2024 00:28:46 +0200
Subject: [PATCH] fix: invalid depth on deco simulation

---
 Cargo.lock                       | 2 +-
 Cargo.toml                       | 2 +-
 src/buehlmann/buehlmann_model.rs | 5 ++++-
 tests/deco_tests.rs              | 4 ++--
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 41d932c..538eee1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,4 +4,4 @@ version = 3
 
 [[package]]
 name = "dive-deco"
-version = "1.3.0"
+version = "1.3.1"
diff --git a/Cargo.toml b/Cargo.toml
index ba236f2..7eb5036 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "dive-deco"
-version = "1.3.0"
+version = "1.3.1"
 edition = "2021"
 license = "MIT"
 description = "A dive decompression models library (Buehlmann ZH-L 16C)"
diff --git a/src/buehlmann/buehlmann_model.rs b/src/buehlmann/buehlmann_model.rs
index 16816d3..c788363 100644
--- a/src/buehlmann/buehlmann_model.rs
+++ b/src/buehlmann/buehlmann_model.rs
@@ -227,7 +227,10 @@ impl BuehlmannModel {
                 let sim_gas = sim_model.state.gas;
                 let mut target_depth = sim_model.state.depth;
                 while target_depth > 0. {
-                    let sim_step_depth = target_depth - 1.;
+                    let mut sim_step_depth = target_depth - 1.;
+                    if sim_step_depth < 0. {
+                        sim_step_depth = 0.;
+                    }
                     sim_model.step(&sim_step_depth, &0, &sim_gas);
                     let Supersaturation { gf_99, .. } = sim_model.supersaturation();
                     if gf_99 >= gf_low.into() {
diff --git a/tests/deco_tests.rs b/tests/deco_tests.rs
index 0d22945..e6c2bec 100644
--- a/tests/deco_tests.rs
+++ b/tests/deco_tests.rs
@@ -75,7 +75,7 @@ fn deco_multi_gas() {
 
     let mut model = fixtures::model_default();
 
-    model.step(&40., &(20 * 60), &air);
+    model.step(&40.0001, &(20 * 60), &air);
 
     let Deco {
         deco_stages,
@@ -87,7 +87,7 @@ fn deco_multi_gas() {
     let expected_deco_stages =  vec![
         DecoStage {
             stage_type: DecoStageType::Ascent,
-            start_depth: 40.0,
+            start_depth: 40.0001,
             end_depth: 22.,
             duration: 120,
             gas: air