dotnet/runtime

Description i was instructed to post the issue here, as its about .NET api main issue when SetEnvironmentVariable() is used that contains a %variable% the registry key is set as reg_sz instead of expanded so the variable is not correctly save and breaking for example the path environment variable or other created variables Proposed technical implementation details (optional) GetEnvironmentVariable() add a new optional parameter that can be used to get a variable not expanded This allows to save it to a variable and pass it directly to SetEnvironmentVariable without breaking %% inside variables also for SetEnvironmentVariable it should detect if a % is inside the parameter and set the korrekt registrykey type when saving (reg_expand_sz) currently it always saves as reg_sz which breaks Path variable when used here the current behaviour is described. for the correct behaviour when creating the reg key (reg_sz or expanded), you can also look here at line 90 https://github.com/microsoft/Po

Description The method ICollection<KeyValuePair<TKey, TValue>>.CopyTo(KeyValuePair<TKey, TValue>[], int) from Dictionary<TKey, TValue> seems to produce an incorrect exception message in some situations, telling that a non-negative index is required when that is not exactly the error that was produced. Reproduction Steps using System.Collections.Generic; Dictionary<int, int> actual = new(); KeyValuePair<int, int>[] array = new KeyValuePair<int, int>[0]; ((ICollection<KeyValuePair<int, int>>)actual).CopyTo(array, array.Length + 1); The same also happens if the dictionary isn't empty or the array has some length. It also happens with non-generic ICollection method. Expected behavior System.ArgumentException: The number of elements in the source is greater than the available space from index to the end of the destination array. (Parameter 'index') (According to documentation) Actual behavior System.ArgumentOutOfRangeException: Non-negative number required. (Parameter 'index') Regression?

Title StringBuilder.ToString() throws misleading ArgumentOutOfRangeException for internal chunk inconsistency Description StringBuilder.ToString() validates internal chunk boundaries before copying: if ((uint)(chunkLength + chunkOffset) > (uint)result.Length || (uint)chunkLength > (uint)sourceArray.Length) { throw new ArgumentOutOfRangeException( nameof(chunkLength), SR.ArgumentOutOfRange_IndexMustBeLessOrEqual); } This exception is misleading: ToString() has no parameters. chunkLength is a private local copied from internal StringBuilder state. The caller cannot provide or correct a parameter named chunkLength. The failed condition indicates an inconsistent internal snapshot, normally caused by concurrent mutation. A real occurrence was reported in #46022. Concurrent use is caller misuse because StringBuilder is not thread-safe, but reporting it as an invalid argument obscures the real cause. Expected behavior Throw an exception representing an invalid or inc

Summary Three distinct problems — agent/LLM token cost, GitHub tool interaction, and GitHub UI/search — all stem from the same root cause: files that have grown without a size budget. This issue tracks candidates for splitting and flags files that break specific documented thresholds. Audit methodology: git ls-tree -r -l HEAD for byte sizes, git show | split for per-file line and max-line-length, git log --oneline --since=2.years for 2-year commit counts. No large files were opened whole; the audit itself was non-destructive. Confirmed thresholds Limit Value Source view tool truncation 20 KB Tool documentation Agent token cost morph.cpp (~585 KB) ≈ 137k tokens ≈ 200 AI credits per full read Measured in this repo (tiktoken/o200k_base) Code search file exclusion > 350 KiB docs.github.com Code search line truncation Lines > 1,024 chars Same Code search full exclusion Files with > 1 line over 4,096 bytes Same Per-PR diff > 20,000 lines or > 1 MB docs.github.com

Not sure if these were missed or intentionally left out. It refers to e.g. runtime/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.cs Lines 938 to 961 in 8f65ed7 public static unsafe int IndexOfAnyExcept<T>(this ReadOnlySpan<T> span, T value0, T value1) where T : IEquatable<T>? { if (RuntimeHelpers.IsBitwiseEquatable<T>()) { if (sizeof(T) == sizeof(byte)) { return SpanHelpers.IndexOfAnyExceptValueType( ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(span)), Unsafe.BitCast<T,