From ba850faa1b510e34dd4edd6b3f3d61d13687eda6 Mon Sep 17 00:00:00 2001
From: nick evans <nick@rubinick.dev>
Date: Wed, 11 Feb 2026 13:16:31 -0500
Subject: [PATCH 1/2] =?UTF-8?q?=F0=9F=90=9B=20Return=20ResponseText=20from?=
 =?UTF-8?q?=20`resp-text`=20fallback?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This bug was introduced in #601, which hasn't been released yet.
---
 lib/net/imap/response_parser.rb                   |  2 +-
 .../fixtures/response_parser/quirky_behaviors.yml | 15 +++++++--------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/lib/net/imap/response_parser.rb b/lib/net/imap/response_parser.rb
index 2c1d1dd1..7b616bfa 100644
--- a/lib/net/imap/response_parser.rb
+++ b/lib/net/imap/response_parser.rb
@@ -1898,7 +1898,7 @@ def resp_text
       rescue ResponseParseError => error
         raise if /\buid-set\b/i.match? error.message
         restore_state state
-        text
+        ResponseText.new(nil, text? || "")
       end
 
       # RFC3501 (See https://www.rfc-editor.org/errata/rfc3501):
diff --git a/test/net/imap/fixtures/response_parser/quirky_behaviors.yml b/test/net/imap/fixtures/response_parser/quirky_behaviors.yml
index f6f3e790..1bef93aa 100644
--- a/test/net/imap/fixtures/response_parser/quirky_behaviors.yml
+++ b/test/net/imap/fixtures/response_parser/quirky_behaviors.yml
@@ -37,21 +37,20 @@
 
       Microsoft Exchange is issuing an invalid resp-text-code, but net-imap
       should fallback to `resp-text = text` when resp-text-code fails to parse.
-    :debug: false # current version of backtracking still prints parse_errors
     :response: "RUBY0001 OK [Error=\"Microsoft.Exchange.Data.Storage.WrongServerException:
       Cross Server access is not allowed for mailbox xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx\"
       AuthResultFromPopImapEnd=0 Proxy=XXXXXXXXXXXXX.EURXXXX.PROD.OUTLOOK.COM:1993:SSL
       MailboxBE=XXXXXXXXXXXXX.EURXXXX.PROD.OUTLOOK.COM
       Service=Imap4] AUTHENTICATE completed.\r\n"
     :expected: !ruby/struct:Net::IMAP::TaggedResponse
-      tag:  RUBY0001
+      tag: RUBY0001
       name: OK
-      data: '[Error="Microsoft.Exchange.Data.Storage.WrongServerException: Cross Server
-        access is not allowed for mailbox xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
-        AuthResultFromPopImapEnd=0
-        Proxy=XXXXXXXXXXXXX.EURXXXX.PROD.OUTLOOK.COM:1993:SSL
-        MailboxBE=XXXXXXXXXXXXX.EURXXXX.PROD.OUTLOOK.COM Service=Imap4]
-        AUTHENTICATE completed.'
+      data: !ruby/struct:Net::IMAP::ResponseText
+        code:
+        text: '[Error="Microsoft.Exchange.Data.Storage.WrongServerException: Cross Server
+          access is not allowed for mailbox xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" AuthResultFromPopImapEnd=0
+          Proxy=XXXXXXXXXXXXX.EURXXXX.PROD.OUTLOOK.COM:1993:SSL MailboxBE=XXXXXXXXXXXXX.EURXXXX.PROD.OUTLOOK.COM
+          Service=Imap4] AUTHENTICATE completed.'
       raw_data: "RUBY0001 OK [Error=\"Microsoft.Exchange.Data.Storage.WrongServerException:
         Cross Server access is not allowed for mailbox xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx\"
         AuthResultFromPopImapEnd=0 Proxy=XXXXXXXXXXXXX.EURXXXX.PROD.OUTLOOK.COM:1993:SSL

From 78c204d20008e16e62f6afdebcc44be333e97a08 Mon Sep 17 00:00:00 2001
From: nick evans <nick@rubinick.dev>
Date: Wed, 11 Feb 2026 13:22:11 -0500
Subject: [PATCH 2/2] =?UTF-8?q?=E2=99=BB=EF=B8=8F=20Use=20tighter=20scope?=
 =?UTF-8?q?=20for=20resp-text=20backtracking?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This scopes the backtracking _only_ around the `"[" resp-text-code "]"`
case.  The `else` clause and the `rescue` fallback can now execute the
same code.  In addition to reducing duplication of code, this also
potentially reduces _work_, since there's no point in rescuing the
`else` clause only to try the exact same thing again.
---
 lib/net/imap/response_parser.rb | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/lib/net/imap/response_parser.rb b/lib/net/imap/response_parser.rb
index 7b616bfa..b6fbc264 100644
--- a/lib/net/imap/response_parser.rb
+++ b/lib/net/imap/response_parser.rb
@@ -1888,16 +1888,16 @@ def text?
       # We leniently re-interpret this as
       #   resp-text       = ["[" resp-text-code "]" [SP [text]] / [text]
       def resp_text
-        state = current_state
-        if lbra?
-          code = resp_text_code; rbra
-          ResponseText.new(code, SP? && text? || "")
-        else
-          ResponseText.new(nil, text? || "")
+        begin
+          state = current_state
+          if lbra?
+            code = resp_text_code; rbra
+            return ResponseText.new(code, SP? && text? || "")
+          end
+        rescue ResponseParseError => error
+          raise if /\buid-set\b/i.match? error.message
+          restore_state state
         end
-      rescue ResponseParseError => error
-        raise if /\buid-set\b/i.match? error.message
-        restore_state state
         ResponseText.new(nil, text? || "")
       end