From 0d5ba595d6a5b31f47ed57780779302495c1c8c0 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 8 Apr 2026 23:43:02 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Fix=20O(N^2)=20vector=20erasure=20i?=
 =?UTF-8?q?n=20ISO=20demuxer=20error=20recovery?=
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Refactored the sample chunk validation loop in `ErrorRecovery::RepairSampleToChunkTable` to use the erase-remove idiom instead of repeatedly calling `vector::erase` inside a loop.

This replaces O(N^2) shifting operations with an O(N) single-pass shift.

The duplicate logging behavior has been intentionally maintained by comparing container sizes pre- and post-erasure and logging proportionally.

Co-authored-by: segin <480709+segin@users.noreply.github.com>
---
 src/demuxer/iso/ErrorRecovery.cpp | 20 ++++++++++++--------
 util/build-deps.sh                |  0
 2 files changed, 12 insertions(+), 8 deletions(-)
 mode change 100644 => 100755 util/build-deps.sh

diff --git a/src/demuxer/iso/ErrorRecovery.cpp b/src/demuxer/iso/ErrorRecovery.cpp
index 19183790..c0281244 100644
--- a/src/demuxer/iso/ErrorRecovery.cpp
+++ b/src/demuxer/iso/ErrorRecovery.cpp
@@ -199,14 +199,18 @@ bool ErrorRecovery::RepairSampleToChunkTable(SampleTableInfo& tables) {
     }
     
     // Check for invalid entries in sample-to-chunk table
-    for (auto it = tables.sampleToChunkEntries.begin(); it != tables.sampleToChunkEntries.end(); ) {
-        if (it->samplesPerChunk == 0 || it->sampleDescIndex == 0) {
-            // Invalid entry, remove it
-            it = tables.sampleToChunkEntries.erase(it);
-            LogError("ChunkTableRepair", "Removed invalid sample-to-chunk entry");
-        } else {
-            ++it;
-        }
+    size_t originalSize = tables.sampleToChunkEntries.size();
+    tables.sampleToChunkEntries.erase(
+        std::remove_if(tables.sampleToChunkEntries.begin(), tables.sampleToChunkEntries.end(),
+            [](const auto& entry) {
+                return entry.samplesPerChunk == 0 || entry.sampleDescIndex == 0;
+            }),
+        tables.sampleToChunkEntries.end()
+    );
+
+    size_t removedCount = originalSize - tables.sampleToChunkEntries.size();
+    for (size_t i = 0; i < removedCount; ++i) {
+        LogError("ChunkTableRepair", "Removed invalid sample-to-chunk entry");
     }
     
     // If all entries were invalid, create a default entry
diff --git a/util/build-deps.sh b/util/build-deps.sh
old mode 100644
new mode 100755