Merge #18922: gui: Do not translate InitWarning messages in debug.log

78be8d97d3d750fcfbbe509a72639b7b30b7bd18 util: Drop OpOriginal() and OpTranslated() (Hennadii Stepanov)
da16f95c3fecf4ee1e9a1dc4333b0b92cd981afd gui: Do not translate InitWarning messages in debug.log (Hennadii Stepanov)
4c9b9a4882e68835f16a52f1f0657efe47e589b5 util: Enhance Join() (Hennadii Stepanov)
fe05dd0611cfc2929a7fdec04ca5948bccf0233b util: Enhance bilingual_str (Hennadii Stepanov)

Pull request description:

  This PR forces the `bitcoin-qt` to write `InitWarning()` messages to the `debug.log` file in untranslated form, i.e., in English.

  On master (376294cde6b1588cb17055d8fde567eaf5848c3c):
  ```
  $ ./src/qt/bitcoin-qt -lang=nl -debug=vladidation -printtoconsole | grep 'vladi'
  Warning: Niet-ondersteunde logcategorie -debug=vladidation.
  2020-05-09T12:39:59Z Warning: Niet-ondersteunde logcategorie -debug=vladidation.
  2020-05-09T12:40:02Z Command-line arg: debug="vladidation"
  ```

  With this PR:
  ```
  $ ./src/qt/bitcoin-qt -lang=nl -debug=vladidation -printtoconsole | grep 'vladi'
  Warning: Unsupported logging category -debug=vladidation.
  2020-05-09T12:42:04Z Warning: Unsupported logging category -debug=vladidation.
  2020-05-09T12:42:35Z Command-line arg: debug="vladidation"
  ```

  ![Screenshot from 2020-05-09 15-42-31](https://user-images.githubusercontent.com/32963518/81474073-c7a50e00-920b-11ea-8775-c41122dacafe.png)

  Related to #16218.

ACKs for top commit:
  laanwj:
    ACK 78be8d97d3d750fcfbbe509a72639b7b30b7bd18
  jonasschnelli:
    utACK 78be8d97d3d750fcfbbe509a72639b7b30b7bd18
  MarcoFalke:
    ACK 78be8d97d3d750fcfbbe509a72639b7b30b7bd18 📢

Tree-SHA512: 48e9ecd23c4dd8ec262e3eb94f8e30944bcc9c6c163245fb837b2e0c484d4d0b4f47f7abc638c14edc27d635d340ba3ee4ba4506b062399e9cf59a1564c98755

10 files changed, 38 insertions, 29 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 2653bd25a6..3b97ba08d9 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -972,7 +972,7 @@ bool AppInitParameterInteraction()
 
     // Warn if unrecognized section name are present in the config file.
     for (const auto& section : gArgs.GetUnrecognizedSections()) {
-        InitWarning(strprintf("%s:%i " + _("Section [%s] is not recognized.").translated, section.m_file, section.m_line, section.m_name));
+        InitWarning(strprintf(Untranslated("%s:%i ") + _("Section [%s] is not recognized."), section.m_file, section.m_line, section.m_name));
     }
 
     if (!fs::is_directory(GetBlocksDir())) {
@@ -1035,7 +1035,7 @@ bool AppInitParameterInteraction()
     nMaxConnections = std::min(nFD - MIN_CORE_FILEDESCRIPTORS - MAX_ADDNODE_CONNECTIONS, nMaxConnections);
 
     if (nMaxConnections < nUserMaxConnections)
-        InitWarning(strprintf(_("Reducing -maxconnections from %d to %d, because of system limitations.").translated, nUserMaxConnections, nMaxConnections));
+        InitWarning(strprintf(_("Reducing -maxconnections from %d to %d, because of system limitations."), nUserMaxConnections, nMaxConnections));
 
     // ********************************************************* Step 3: parameter-to-internal-flags
     if (gArgs.IsArgSet("-debug")) {
@@ -1046,7 +1046,7 @@ bool AppInitParameterInteraction()
             [](std::string cat){return cat == "0" || cat == "none";})) {
             for (const auto& cat : categories) {
                 if (!LogInstance().EnableCategory(cat)) {
-                    InitWarning(strprintf(_("Unsupported logging category %s=%s.").translated, "-debug", cat));
+                    InitWarning(strprintf(_("Unsupported logging category %s=%s."), "-debug", cat));
                 }
             }
         }
@@ -1055,7 +1055,7 @@ bool AppInitParameterInteraction()
     // Now remove the logging categories which were explicitly excluded
     for (const std::string& cat : gArgs.GetArgs("-debugexclude")) {
         if (!LogInstance().DisableCategory(cat)) {
-            InitWarning(strprintf(_("Unsupported logging category %s=%s.").translated, "-debugexclude", cat));
+            InitWarning(strprintf(_("Unsupported logging category %s=%s."), "-debugexclude", cat));
         }
     }
 
@@ -1268,7 +1268,7 @@ bool AppInitMain(NodeContext& node)
         LogPrintf("Config file: %s\n", config_file_path.string());
     } else if (gArgs.IsArgSet("-conf")) {
         // Warn if no conf file exists at path provided by user
-        InitWarning(strprintf(_("The specified config file %s does not exist\n").translated, config_file_path.string()));
+        InitWarning(strprintf(_("The specified config file %s does not exist\n"), config_file_path.string()));
     } else {
         // Not categorizing as "Warning" because it's the default behavior
         LogPrintf("Config file: %s (not found, skipping)\n", config_file_path.string());
diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index e1a528d99c..d8e459a8e8 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -344,7 +344,7 @@ public:
     bool shutdownRequested() override { return ShutdownRequested(); }
     int64_t getAdjustedTime() override { return GetAdjustedTime(); }
     void initMessage(const std::string& message) override { ::uiInterface.InitMessage(message); }
-    void initWarning(const std::string& message) override { InitWarning(message); }
+    void initWarning(const bilingual_str& message) override { InitWarning(message); }
     void initError(const bilingual_str& message) override { InitError(message); }
     void showProgress(const std::string& title, int progress, bool resume_possible) override
     {
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index 77b315b195..7dfc77db7b 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -225,7 +225,7 @@ public:
     virtual void initMessage(const std::string& message) = 0;
 
     //! Send init warning.
-    virtual void initWarning(const std::string& message) = 0;
+    virtual void initWarning(const bilingual_str& message) = 0;
 
     //! Send init error.
     virtual void initError(const bilingual_str& message) = 0;
diff --git a/src/qt/walletcontroller.cpp b/src/qt/walletcontroller.cpp
index 7cde3ca30b..20f2ef5b5f 100644
--- a/src/qt/walletcontroller.cpp
+++ b/src/qt/walletcontroller.cpp
@@ -248,7 +248,7 @@ void CreateWalletActivity::finish()
     if (!m_error_message.original.empty()) {
         QMessageBox::critical(m_parent_widget, tr("Create wallet failed"), QString::fromStdString(m_error_message.translated));
     } else if (!m_warning_message.empty()) {
-        QMessageBox::warning(m_parent_widget, tr("Create wallet warning"), QString::fromStdString(Join(m_warning_message, "\n", OpTranslated)));
+        QMessageBox::warning(m_parent_widget, tr("Create wallet warning"), QString::fromStdString(Join(m_warning_message, Untranslated("\n")).translated));
     }
 
     if (m_wallet_model) Q_EMIT created(m_wallet_model);
@@ -289,7 +289,7 @@ void OpenWalletActivity::finish()
     if (!m_error_message.original.empty()) {
         QMessageBox::critical(m_parent_widget, tr("Open wallet failed"), QString::fromStdString(m_error_message.translated));
     } else if (!m_warning_message.empty()) {
-        QMessageBox::warning(m_parent_widget, tr("Open wallet warning"), QString::fromStdString(Join(m_warning_message, "\n", OpTranslated)));
+        QMessageBox::warning(m_parent_widget, tr("Open wallet warning"), QString::fromStdString(Join(m_warning_message, Untranslated("\n")).translated));
     }
 
     if (m_wallet_model) Q_EMIT opened(m_wallet_model);
diff --git a/src/ui_interface.cpp b/src/ui_interface.cpp
index 9cfde9502d..bb41154afc 100644
--- a/src/ui_interface.cpp
+++ b/src/ui_interface.cpp
@@ -59,7 +59,7 @@ bool InitError(const bilingual_str& str)
     return false;
 }
 
-void InitWarning(const std::string& str)
+void InitWarning(const bilingual_str& str)
 {
-    uiInterface.ThreadSafeMessageBox(Untranslated(str), "", CClientUIInterface::MSG_WARNING);
+    uiInterface.ThreadSafeMessageBox(str, "", CClientUIInterface::MSG_WARNING);
 }
diff --git a/src/ui_interface.h b/src/ui_interface.h
index 132866cc5a..9c49451e84 100644
--- a/src/ui_interface.h
+++ b/src/ui_interface.h
@@ -120,8 +120,7 @@ public:
 };
 
 /** Show warning message **/
-// TODO: InitWarning() should take a bilingual_str parameter.
-void InitWarning(const std::string& str);
+void InitWarning(const bilingual_str& str);
 
 /** Show error message **/
 bool InitError(const bilingual_str& str);
diff --git a/src/util/string.h b/src/util/string.h
index b8e2a06235..cdb41630c6 100644
--- a/src/util/string.h
+++ b/src/util/string.h
@@ -30,10 +30,11 @@ NODISCARD inline std::string TrimString(const std::string& str, const std::strin
  * @param separator  The separator
  * @param unary_op   Apply this operator to each item in the list
  */
-template <typename T, typename UnaryOp>
-std::string Join(const std::vector<T>& list, const std::string& separator, UnaryOp unary_op)
+template <typename T, typename BaseType, typename UnaryOp>
+auto Join(const std::vector<T>& list, const BaseType& separator, UnaryOp unary_op)
+    -> decltype(unary_op(list.at(0)))
 {
-    std::string ret;
+    decltype(unary_op(list.at(0))) ret;
     for (size_t i = 0; i < list.size(); ++i) {
         if (i > 0) ret += separator;
         ret += unary_op(list.at(i));
@@ -41,9 +42,16 @@ std::string Join(const std::vector<T>& list, const std::string& separator, Unary
     return ret;
 }
 
+template <typename T>
+T Join(const std::vector<T>& list, const T& separator)
+{
+    return Join(list, separator, [](const T& i) { return i; });
+}
+
+// Explicit overload needed for c_str arguments, which would otherwise cause a substitution failure in the template above.
 inline std::string Join(const std::vector<std::string>& list, const std::string& separator)
 {
-    return Join(list, separator, [](const std::string& i) { return i; });
+    return Join<std::string>(list, separator);
 }
 
 /**
diff --git a/src/util/translation.h b/src/util/translation.h
index 45595405e7..268bcf30a7 100644
--- a/src/util/translation.h
+++ b/src/util/translation.h
@@ -16,21 +16,23 @@
 struct bilingual_str {
     std::string original;
     std::string translated;
+
+    bilingual_str& operator+=(const bilingual_str& rhs)
+    {
+        original += rhs.original;
+        translated += rhs.translated;
+        return *this;
+    }
 };
 
-inline bilingual_str operator+(const bilingual_str& lhs, const bilingual_str& rhs)
+inline bilingual_str operator+(bilingual_str lhs, const bilingual_str& rhs)
 {
-    return bilingual_str{
-        lhs.original + rhs.original,
-        lhs.translated + rhs.translated};
+    lhs += rhs;
+    return lhs;
 }
 
 /** Mark a bilingual_str as untranslated */
 inline bilingual_str Untranslated(std::string original) { return {original, original}; }
-/** Unary operator to return the original */
-inline std::string OpOriginal(const bilingual_str& b) { return b.original; }
-/** Unary operator to return the translation */
-inline std::string OpTranslated(const bilingual_str& b) { return b.translated; }
 
 namespace tinyformat {
 template <typename... Args>
diff --git a/src/wallet/load.cpp b/src/wallet/load.cpp
index 45841b2ae1..16f3699d37 100644
--- a/src/wallet/load.cpp
+++ b/src/wallet/load.cpp
@@ -56,7 +56,7 @@ bool VerifyWallets(interfaces::Chain& chain, const std::vector<std::string>& wal
         bilingual_str error_string;
         std::vector<bilingual_str> warnings;
         bool verify_success = CWallet::Verify(chain, location, salvage_wallet, error_string, warnings);
-        if (!warnings.empty()) chain.initWarning(Join(warnings, "\n", OpTranslated));
+        if (!warnings.empty()) chain.initWarning(Join(warnings, Untranslated("\n")));
         if (!verify_success) {
             chain.initError(error_string);
             return false;
@@ -73,7 +73,7 @@ bool LoadWallets(interfaces::Chain& chain, const std::vector<std::string>& walle
             bilingual_str error;
             std::vector<bilingual_str> warnings;
             std::shared_ptr<CWallet> pwallet = CWallet::CreateWalletFromFile(chain, WalletLocation(walletFile), error, warnings);
-            if (!warnings.empty()) chain.initWarning(Join(warnings, "\n", OpTranslated));
+            if (!warnings.empty()) chain.initWarning(Join(warnings, Untranslated("\n")));
             if (!pwallet) {
                 chain.initError(error);
                 return false;
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index c2d314140c..250a4503f5 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -2603,7 +2603,7 @@ static UniValue loadwallet(const JSONRPCRequest& request)
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
-    obj.pushKV("warning", Join(warnings, "\n", OpOriginal));
+    obj.pushKV("warning", Join(warnings, Untranslated("\n")).original);
 
     return obj;
 }
@@ -2743,7 +2743,7 @@ static UniValue createwallet(const JSONRPCRequest& request)
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
-    obj.pushKV("warning", Join(warnings, "\n", OpOriginal));
+    obj.pushKV("warning", Join(warnings, Untranslated("\n")).original);
 
     return obj;
 }