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IDProjectCategoryView StatusLast Update
0011934Talerwallet (iOS App)public2026-11-04 13:01
Reporterbot-cg [agent] Assigned ToResolution deadline
ImplementerMarcS ReviewerChristian Grothoff  
Release signed byMarcS Deployed byMarcS  
VerifierCommunicator 
Data protection authority notification requiredNo  
CSIRT notification requiredNo  
Estimated effort (hours)Actual effort (hours)0 
Fast-trackNo
Work packagenone
PrioritynormalSeverityminorReproducibilityhave not tried
Status planningResolutionopen 
Product Version1.6 
Target Version1.7 
Summary0011934: Withdraw / Loading: expected wallet-core errors are titled "Internal core error" (e.g. 7054 withdrawal limit exceeded), with raw JSON as the body
DescriptionEntering a withdrawal amount larger than the payment service allows is an
ordinary, expected outcome. The wallet presents it as an internal fault:

    Internal core error

    {
      "when" : { "t_s" : 1793753531 },
      "code" : 7054,
      "hint" : "withdrawal would exceed a hard limit of the exchange"
    }

    [ Copy the error JSON ] [ OK ]

Code 7054 is WALLET_KYC_LIMIT_EXCEEDED: "the operation would exceed a limit
imposed by the exchange that the user cannot raise by completing a KYC
process". Nothing went wrong inside the wallet. The user is told they hit an
internal error, and is offered a button to copy a JSON blob.

Cause
-----

TalerWallet1/Views/Main/ErrorView.swift maps exactly six wallet-core codes to
meaningful titles:

    if code == 7002 || code == 7003 || code == 7005 ||
       code == 7032 || code == 7036 || code == 7049 { ... }

Every other code falls through to `walletCoreError`, which is
String(localized: "Internal core error"). Both remaining branches use that
title -- the hint branch taken in release builds and the JSON branch taken
in developer mode -- so the title is wrong regardless of build configuration.
Only the body differs: a release build shows the hint, a developer build shows
the raw JSON seen above.

Other codes in the same class are affected identically, among them
7055 WALLET_NO_SUITABLE_EXCHANGE, 7064 WALLET_CONTRACT_TERMS_UNSUPPORTED, and
the two protocol-version incompatibilities 7000 and 7017. A user whose wallet
is too old for an exchange is also told it is an internal core error.

Observed on screen "Loading..." while a manual withdrawal was being confirmed
(sheet 135, ManualWithdraw). The surrounding controls were "Withdraw Fr.",
"Cancel", the error text above, "Copy the error JSON" and "OK".

How to reproduce
----------------
By hand
-------

    1. open the wallet, choose Withdraw for any currency
    2. in the amount field enter a value far above the service's limit --
       the exploration harness types 99999999999999999999 from its input corpus
    3. confirm the withdrawal
    4. the error view appears, titled "Internal core error"

With the exploration harness
----------------------------

The harness found this while walking the withdrawal flow with hostile input.
The episode is camp3-e00006; its observations contain the rendered text quoted
above. To re-run that exact walk, from harness/ on a Mac with Xcode:

    python3 -m taler_fuzz build
    python3 -m taler_fuzz --max-steps 90 replay \
        --tape "7,8,0,0,0,0,0,0,0,15,2,4,11,0,11,15,14,9,0,7,5,15,15,10,2,8,4,12,6,10,9,12,1,6,1,10,7,10,14,7,8,11,5,8,9,0,11,1,4,11,0,15,1,0,7,1,3,7,10,2,1,11,13,4,6,14,13,4,11,9,5,10,13,12,0,13,5,0,15,13,9,11,12,8,4,0,14,2,10,1" \
        --label kyclimit --shots

Note this walk reaches the condition against the live demo services, so it
depends on their current limits.

Deterministically, without needing the real condition
-----------------------------------------------------

wallet-core's api-error experiment returns any code from any operation, and the
harness wraps that:

    python3 -m taler_fuzz replay --tape "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0" \
        --label limit --fault core.err_limit --shots

which delivers

    taler://dev-experiment/api-error?operation=getBalances
        &detail=<base64url {"code":7054,"hint":"..."}>&count=3

to the running app. The harness asserts that an error of this class is not
presented with an internal-fault title; `core.err_no_exchange`,
`core.err_proto_exchange`, `core.err_proto_bank` and `core.err_contract` cover
the sibling codes. This needs the GNU_Taler or Taler_Nightly flavour, which
are the ones that compile in the dev-experiment handler.

Patch
-----

Attached: fix-internal-core-error.patch (one file, +42), against master; also
branch dev/phoenix-bot/fix-internal-core-error.

It adds ErrorView.titleForExpected(code:), consulted before the generic
branches, giving a title to the codes that are expected outcomes:

    7054 WALLET_KYC_LIMIT_EXCEEDED -> "Limit exceeded"
    7055 WALLET_NO_SUITABLE_EXCHANGE -> "No suitable payment service"
    7064 WALLET_CONTRACT_TERMS_UNSUPPORTED -> "Transaction Error" (existing string)
    7000 / 7017 protocol version incompatible -> "Incompatible version"

An unrecognised code still falls through to the existing behaviour, so no other
error can be made worse. The hint becomes the message, and the JSON stays
available in developer mode only.

Every code above was checked against taler-error-codes.ts rather than guessed.

Two things for the maintainer to decide, which is why this is a proposal rather
than a finished change:

  * the two new titles are new localizable strings and have no translations
    yet, so they would render in English until the catalogue is updated;
  * whether showing a raw JSON blob in developer mode is wanted at all on a
    user-facing error view, or whether it belongs behind "Copy the error JSON"
    alone.

Verification status, stated plainly: the patch compiles for the simulator and
its logic is a single switch consulted before the existing branches. I
reproduced the defect itself from a real run, and I verified the injection
channel used by the regression fault reaches wallet-core
("applying dev experiment ... api-error ... getBalances" in the app log), but I
did not manage to re-provoke the exact on-screen presentation within a short
walk, so I have not watched the patched title appear. A screenshot of the
unpatched presentation is likewise not attached; the verbatim on-screen text is
quoted above from the episode's recorded accessibility tree.

Estimated severity
------------------
Medium - wrong or confusing presentation; the flow still completes.

Estimated effort to fix
-----------------------
Small - a few hours. The change itself is one switch in ErrorView.swift. The time goes into agreeing which codes count as expected outcomes, wording their titles, and adding those strings to Localizable.xcstrings for the six shipped languages.

Filed by an agent (bot-cg) on behalf of Christian Grothoff, from an
automated UI exploration campaign. Left unassigned deliberately.
TagsNo tags attached.
Attached Files
fix-internal-core-error.patch (3,337 bytes)   
diff --git a/TalerWallet1/Views/Main/ErrorView.swift b/TalerWallet1/Views/Main/ErrorView.swift
index af392083..8b8e4d21 100644
--- a/TalerWallet1/Views/Main/ErrorView.swift
+++ b/TalerWallet1/Views/Main/ErrorView.swift
@@ -102,6 +102,31 @@ enum ErrorData {
 }
 
 struct ErrorView: View {
+
+    /// Title for wallet-core errors that are expected outcomes rather than
+    /// faults, keyed by `TalerErrorCode`.
+    ///
+    /// Returning nil means "no better title than the generic one", so an
+    /// unrecognised code still falls through to the existing behaviour.
+    static func titleForExpected(code: Int) -> String? {
+        switch code {
+            case 7054:          // WALLET_KYC_LIMIT_EXCEEDED
+                return String(localized: "Limit exceeded",
+                              comment: "error title: the payment service refused the amount")
+            case 7055:          // WALLET_NO_SUITABLE_EXCHANGE
+                return String(localized: "No suitable payment service",
+                              comment: "error title: no exchange can serve this request")
+            case 7064:          // WALLET_CONTRACT_TERMS_UNSUPPORTED
+                return String(localized: "Transaction Error")
+            case 7000,          // WALLET_EXCHANGE_PROTOCOL_VERSION_INCOMPATIBLE
+                 7017:          // WALLET_BANK_INTEGRATION_PROTOCOL_VERSION_INCOMPATIBLE
+                return String(localized: "Incompatible version",
+                              comment: "error title: the server speaks a protocol this app does not")
+            default:
+                return nil
+        }
+    }
+
     let stack: CallStack?
     var title: String
     var exclam: Bool
@@ -152,6 +177,23 @@ struct ErrorView: View {
                                 break
                             }
                             let hint = responseError.errorResponse?.hint ?? responseError.hint      // nested one preferred
+                            // Not every wallet-core error is an internal fault.
+                            // Limits, quotas and similar conditions are ordinary
+                            // outcomes the user can act on, and titling them
+                            // "Internal core error" tells them they hit a bug when
+                            // they did not. Give those a title that matches what
+                            // happened; anything genuinely unexpected keeps the
+                            // internal-error title.
+                            let expectedTitle = ErrorView.titleForExpected(code: code)
+                            if let expectedTitle {
+                                self.init(stack, title: expectedTitle,
+                                         exclam: false,
+                                        message: hint,
+                                     requestUrl: responseError.requestUrl,
+                                       copyable: devMode,
+                                      onDismiss: onDismiss)
+                                break
+                            }
                             if !devMode, let hint {
                                 // prefer hint for regular users
                                 self.init(stack, title: walletCoreError, message: hint, copyable: true, onDismiss: onDismiss)
fix-internal-core-error.patch (3,337 bytes)   
before-internal-core-error.png (112,478 bytes)   
before-internal-core-error.png (112,478 bytes)   
after-incompatible-version.png (104,387 bytes)   
after-incompatible-version.png (104,387 bytes)   

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Questions

Put toAsked byStatusNote
MarcSChristian Grothoffwaiting for an answer30,234
 
A question is put to one person and moves the issue nowhere: it can be assigned, worked on and implemented with a question open, because whoever asked is the one who knows whether the answer still matters. Several may be open at once. The question itself is the note, so it is formatted, notified and in the record like everything else anybody said here.

The plan

IDSummaryStatusAssigned ToEstimated effort (hours)
This issue has no child issue. Work that is big enough to be divided is divided here, and each part is planned on its own.
This issue (hours)
Its children (hours)0
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Nothing is missing: the plan can be finished.

Activities

bot-cg [agent]

2026-11-04 02:59

updater   ~0030221

Now reproducible on demand, which closes the verification gap noted when this
was filed.

The harness injects the code directly through wallet-core's api-error
experiment, so the real condition no longer has to be provoked. From harness/
on a Mac with Xcode:

    python3 -m taler_fuzz build
    python3 -m taler_fuzz replay --tape "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0" \
        --label limit --fault core.err_limit --shots

core.err_limit delivers

    taler://dev-experiment/api-error?operation=getBalances
        &detail=<base64url {"code":7054,"hint":"withdrawal would exceed a hard
                            limit of the exchange"}>&count=3

to the running app. Observed in campaign episode camp4-e00018, fault applied
9.5 s into the walk; the "Payment Services" screen then rendered, verbatim from
the recorded accessibility tree:

    Internal core error
    {
      "hint" : "withdrawal would exceed a hard limit of the exchange",
      "code" : 7054
    }
    [ Copy the error JSON ] [ OK ]

So the title is "Internal core error" even on a screen that has nothing to do
with withdrawals -- the error is presented wherever the failing call happens to
surface, here the payment-services list.

The two protocol-version codes behave the same way under
core.err_proto_exchange (7000) and core.err_proto_bank (7017): an error is
shown, and nothing in it mentions a version or suggests updating.

These four faults -- core.err_limit, core.err_no_exchange,
core.err_proto_exchange, core.err_proto_bank, core.err_contract -- assert that
an error of this class is not presented with an internal-fault title, so they
also serve as the regression test for the attached patch.

bot-cg [agent]

2026-11-04 08:38

updater   ~0030226

Patch verified on the running app, with screenshots of both sides.

Earlier I could only say the patch compiled. It is now an A/B on one walk:
the same 90-step tape, the same injected fault, two builds.

Attached
--------
  before-internal-core-error.png the app without the patch
  after-incompatible-version.png the app with it

Both are step 21 of the same replay.

What the two runs show
----------------------
Without the patch:

    Internal core error
    {
      "code" : 7017,
      "hint" : "bank integration protocol version is not compatible"
    }

With the patch, same code, same walk:

    Incompatible version
    bank integration protocol version is not compatible

The harness's own oracle agrees independently: the run without the patch
raises

    [high] fault-misdescribed: expected_error reported as "internal core error"

and the run with it does not -- the only thing left is a low-severity note
that wallet-core returned 7017, which is true and is not a complaint about
the presentation.

How to re-run it
----------------
The episode that recorded the defect in the first place is camp7-e00046; its
tape is replayed directly. On branch dev/phoenix-bot/fuzzbang, under
harness/:

    TAPE=$(python3 -c 'import json;
        d=json.load(open("$work_dir/out/camp7-e00046/episode.json"));
        print(",".join(str(v) for v in d["tape"]))')

    # without the patch
    git checkout dev/phoenix-bot/fuzzbang && python3 -m taler_fuzz build
    python3 -m taler_fuzz --max-steps 90 replay --tape "$TAPE" \
        --fault core.err_proto_bank --shots --label title-before

    # with it
    git checkout dev/phoenix-bot/verify-errtitle && python3 -m taler_fuzz build
    python3 -m taler_fuzz --max-steps 90 replay --tape "$TAPE" \
        --fault core.err_proto_bank --shots --label title-after

`core.err_proto_bank` hands wallet-core a taler://dev-experiment/api-error
URI that makes getBalances return 7017 three times. The error view appears
at step 21 and stays for the rest of the walk; 71 of the recorded screens
contain it, so it is not a timing fluke.

A note on reaching this view at all
-----------------------------------
Two earlier attempts injected the same class of error into
acceptManualWithdrawal and never reached an error view: the walk confirmed
the withdrawal and went to the wire-transfer screen as if nothing had
happened. getBalances is the operation that reliably carries an injected
error, because the app calls it constantly. If you are adding more of these,
inject there.

Added by an agent (bot-cg) on behalf of Christian Grothoff.

Christian Grothoff

2026-11-04 09:56

manager   ~0030234

Please add time estimate.

Issue History

Date ModifiedUsernameFieldChange
2026-11-04 01:06bot-cgNew Issue
2026-11-04 01:06bot-cgFile Added: fix-internal-core-error.patch
2026-11-04 02:59bot-cgNote Added: 0030221
2026-11-04 08:38bot-cgFile Added: before-internal-core-error.png
2026-11-04 08:38bot-cgFile Added: after-incompatible-version.png
2026-11-04 08:38bot-cgNote Added: 0030226
2026-11-04 09:56Christian GrothoffImplementer => MarcS
2026-11-04 09:56Christian GrothoffReviewer => Christian Grothoff
2026-11-04 09:56Christian GrothoffRelease signed by => MarcS
2026-11-04 09:56Christian GrothoffDeployed by => MarcS
2026-11-04 09:56Christian GrothoffCommunicatorCM_7 =>
2026-11-04 09:56Christian GrothoffProduct Version => 1.6
2026-11-04 09:56Christian GrothoffTarget Version => 1.7
2026-11-04 09:56Christian GrothoffDescription Updated
2026-11-04 09:56Christian GrothoffNote Added: 0030234
2026-11-04 13:01Christian GrothoffStatusnew => planning