Case-insensitive IMAP response parsing (RFC 3501)#116
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Adds UIDPLUS extension support so callers can recover the UIDs the server assigns on APPEND/COPY and target expunges by UID: - appendFullUID: like appendFull, returns the APPENDUID response code - copyUID / copyUIDs / copyUIDR: UID COPY returning the COPYUID code - uidExpunge / uidExpungeR: UID EXPUNGE over a UID set or range New types AppendUID and CopyUID, the UIDSet alias, and the APPENDUID/COPYUID/UIDNOTSTICKY status codes with their parsers. sendCommandWithResponse exposes the tagged ServerResponse so the response codes can be read. The existing appendFull/copyFull keep their old signatures by discarding the UID result. Covered by new parser cases in baseTest and a dedicated imapUIDPlusTest group exercising the API against scripted server responses.
RFC 3501 keywords, response codes, flag names and status attributes are case-insensitive, but the parser matched them with case-sensitive `string`, so any server replying with non-canonical casing (e.g. `ok`, `* search`, `[uidvalidity ...]`, `\seen`) caused a parse error. Adds `stringCI`/`charCI` and applies them throughout the response parser. Along the way the tagged/fatal response handling is factored into `pWithTaggedOrFatal`, `pDone` is split into `pRespCode`/`pRespText`/`pStatusCode`, and string parsing is unified (`pQuotedString`/`pLiteralString`/`pAString`/`pMailboxName`). This also: - surfaces an untagged `* BYE` as a fatal response instead of failing - accepts an empty `* SEARCH` reply (no matches) - accepts a `NIL` hierarchy separator in LIST/LSUB - stops `atomChar` from running past CR/LF Covered by a new caseInsensitiveTest group.
This was referenced Jun 13, 2026
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Stacked on #115 (UIDPLUS). This branch is based on the UIDPLUS branch, so until #115 merges the diff here also shows those commits — the change that belongs to this PR is the single commit "Make IMAP response parsing case-insensitive (RFC 3501)". Please review/merge #115 first; I'll rebase this onto
masterafterwards so the diff narrows to just the parser change.What
RFC 3501 keywords, response codes, flag names and status attributes are case-insensitive, but the response parser matched them with case-sensitive
string. A server replying with non-canonical casing —a001 ok,* search …,[uidvalidity …],\seen— caused a hard parseerror. Several real-world servers (Exchange/Office365 among them) don't use the exact canonical uppercase.This adds
stringCI/charCIand applies them throughout the parser.While restructuring, also fixed
pWithTaggedOrFatalpDoneintopRespCode/pRespText/pStatusCodepQuotedString/pLiteralString/pAString/pMailboxName* BYEas a fatal response (BAD) instead of failing to parse* SEARCHreply (zero matches)NILhierarchy separator inLIST/LSUBatomCharfrom running past CR/LFTests
New
caseInsensitiveTestgroup: lowercase tagged/bracketed status codes, lowercase flags, untagged BYE, empty SEARCH, lowercase SEARCH keyword, NIL LIST separator.cabal testpasses (GHC 9.8.4).🤖 Generated with Claude Code