fix: correct UTF-16 string length computations

[Benoît Cortier (CBenoit)]

Replace legacy string helpers in ironrdp-pdu (to_utf16_bytes, from_utf16_bytes, encode_string, decode_string, etc.) with typed primitives from the ironrdp-str crate.

This is both improving the correctness of UTF-16 string handling, and improving the performance of decoding because ironrdp-str primitives are lazily-validated as opposed to the previously eagerly-validated logic.

Fixes #130

[Benoît Cortier (CBenoit)]

• Add ironrdp-str::ansi module with free-standing helpers for ANSI
  (UTF-8) wire strings: decode_ansi, read_ansi_null_term,
  encoded_ansi_len_{with,without}null, write_ansi{with,without}_null
• Migrate fixed-size Unicode fields (client_name, ime_file_name,
  dig_product_id, timezone names, keyboard_ime_filename, FileDescriptor
  name) to FixedString
• Migrate length-prefixed Unicode fields (ProductInfo/LicenseInformation
  company_name/product_id, FileRenameInformation file_name) to
  CbU32StringNullIncluded
• Migrate PreconnectionBlob v2_payload to CchPrefixedString
• Migrate ANSI fields (scope, channel_name, source_descriptor,
  client_username, client_machine_name) to use ironrdp-str::ansi helpers
• Remove UTF8_NULL_TERMINATOR_SIZE constant and delete utf16.rs
• Add ironrdp-str dependency to ironrdp-cliprdr, ironrdp-connector,
  ironrdp-dvc, ironrdp-rdpdr, ironrdp-server

[github-actions]

Coverage Report 🤖 ⚙️

Past:
Total lines: 37300
Covered lines: 24193 (64.86%)

New:
Total lines: 37258
Covered lines: 24217 (65.00%)

Diff: +0.14%

[this comment will be updated automatically]

[Copilot]

Pull request overview

This PR replaces several ad-hoc UTF-16/ANSI string helpers in ironrdp-pdu (and related crates) with typed wire-string primitives from ironrdp-str, aiming to fix incorrect UTF-16 length computations (Issue #130) and improve decode performance via lazy validation.

Changes:

• Migrate multiple protocol fields from String + legacy helpers to ironrdp-str typed primitives (FixedString, CchString, CbU32String*) for correct UTF-16 sizing and null-terminator handling.
• Introduce ironrdp_str::ansi free functions for UTF-8/ANSI wire string decode/encode/length computations.
• Update tests, fixtures, and crate dependencies across the workspace to use the new string representations.

Reviewed changes

Copilot reviewed 36 out of 37 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
crates/ironrdp-testsuite-core/tests/pcb.rs	Updates PCB tests to use CchString for v2 payloads.
crates/ironrdp-testsuite-core/tests/clipboard/mod.rs	Adjusts expected clipboard file list debug output for FixedString<260>.
crates/ironrdp-testsuite-core/src/core_data.rs	Switches core data fixtures to FixedString fields.
crates/ironrdp-testsuite-core/src/client_info.rs	Switches timezone name fixtures to FixedString<32>.
crates/ironrdp-testsuite-core/Cargo.toml	Adds dependency on ironrdp-str.
crates/ironrdp-str/src/prefixed.rs	Adds CbU32StringNoNull alias for u32 byte-prefixed, non-null-terminated UTF-16 strings.
crates/ironrdp-str/src/lib.rs	Exposes new ansi module behind alloc.
crates/ironrdp-str/src/ansi.rs	Adds ANSI (UTF-8) decode/encode and length helpers.
crates/ironrdp-str/Cargo.toml	Disables lib tests/doctests for the crate.
crates/ironrdp-server/src/capabilities.rs	Updates input capability construction to use FixedString IME filename.
crates/ironrdp-server/Cargo.toml	Adds dependency on ironrdp-str.
crates/ironrdp-rdpdr/src/pdu/efs.rs	Changes FileRenameInformation filename handling to a prefixed string type.
crates/ironrdp-rdpdr/Cargo.toml	Adds dependency on ironrdp-str.
crates/ironrdp-pdu/src/utf16.rs	Removes legacy UTF-16 helper module.
crates/ironrdp-pdu/src/rdp/server_license/server_upgrade_license/tests.rs	Updates license upgrade tests to use CbU32StringNullIncluded.
crates/ironrdp-pdu/src/rdp/server_license/server_upgrade_license/mod.rs	Reworks license info encoding/decoding with ansi + prefixed UTF-16 string types.
crates/ironrdp-pdu/src/rdp/server_license/server_license_request/tests.rs	Updates license request tests to use CbU32StringNullIncluded.
crates/ironrdp-pdu/src/rdp/server_license/server_license_request/mod.rs	Reworks product info and scope strings using ansi + prefixed UTF-16 string types.
crates/ironrdp-pdu/src/rdp/server_license/mod.rs	Removes UTF-8/UTF-16 null terminator size constants no longer needed.
crates/ironrdp-pdu/src/rdp/server_license/client_new_license_request/tests.rs	Updates size computations and product info test data to new string helpers/types.
crates/ironrdp-pdu/src/rdp/server_license/client_new_license_request/mod.rs	Switches username/machine-name blob string handling to ansi helpers.
crates/ironrdp-pdu/src/rdp/client_info.rs	Switches timezone names to FixedString<32> and uses typed decode/encode.
crates/ironrdp-pdu/src/rdp/capability_sets/mod.rs	Uses ansi::decode_ansi for Demand Active source descriptor decoding.
crates/ironrdp-pdu/src/rdp/capability_sets/input/tests.rs	Updates input capability tests for FixedString IME filename.
crates/ironrdp-pdu/src/rdp/capability_sets/input.rs	Switches IME filename to FixedString<32> and typed decode/encode.
crates/ironrdp-pdu/src/pcb.rs	Reworks PCB v2 payload to CchString and updates size/encode/decode accordingly.
crates/ironrdp-pdu/src/lib.rs	Stops exporting removed utf16 module.
crates/ironrdp-pdu/src/gcc/core_data/client.rs	Switches core data fixed-size string fields to FixedString types.
crates/ironrdp-pdu/Cargo.toml	Adds dependency on ironrdp-str.
crates/ironrdp-dvc/src/pdu.rs	Switches DRDYNVC channel name parsing/encoding to ansi helpers.
crates/ironrdp-dvc/Cargo.toml	Adds dependency on ironrdp-str.
crates/ironrdp-connector/src/connection_activation.rs	Constructs FixedString IME filename using truncating helper.
crates/ironrdp-connector/src/connection.rs	Constructs FixedString client/IME/product ID fields using truncating helper.
crates/ironrdp-connector/Cargo.toml	Adds dependency on ironrdp-str.
crates/ironrdp-cliprdr/src/pdu/format_data/file_list.rs	Switches file descriptor name field to FixedString<260> and typed decode/encode.
crates/ironrdp-cliprdr/Cargo.toml	Adds dependency on ironrdp-str.
Cargo.lock	Records new workspace dependency edges on ironrdp-str.

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Pull request overview

Copilot reviewed 38 out of 40 changed files in this pull request and generated 4 comments.

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Copilot reviewed 38 out of 40 changed files in this pull request and generated 1 comment.

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