Bug 2718 - improve the error message when opening a project in a read-only directory.

src/DBConnection.cpp

@@ -63,25 +63,37 @@ bool DBConnection::ShouldBypass()
 }
 
 void DBConnection::SetError(
-   const TranslatableString &msg, const TranslatableString &libraryError)
+   const TranslatableString &msg, const TranslatableString &libraryError, int errorCode)
 {
    wxLogMessage(wxT("Connection msg: %s"), msg.Debug());
+
    if (!libraryError.empty())
       wxLogMessage(wxT("Connection error: %s"), libraryError.Debug());
 
    mpErrors->mLastError = msg;
    mpErrors->mLibraryError = libraryError;
+   mpErrors->mErrorCode = errorCode;
 }
 
 void DBConnection::SetDBError(
-   const TranslatableString &msg, const TranslatableString &libraryError)
+   const TranslatableString &msg, const TranslatableString &libraryError, int errorCode)
 {
+    mpErrors->mErrorCode = errorCode < 0 ?
+        sqlite3_errcode(DB()) : errorCode;
+
    mpErrors->mLastError = msg;
-   wxLogMessage(wxT("SQLite error: %s"), mpErrors->mLastError.Debug());
+
+   wxLogMessage(
+       wxT("SQLite error (%d): %s"), 
+       mpErrors->mErrorCode, 
+       mpErrors->mLastError.Debug()
+   );
+
    printf("SQLite error: %s", mpErrors->mLastError.Debug().mb_str().data());
 
    mpErrors->mLibraryError = libraryError.empty()
       ? Verbatim(sqlite3_errmsg(DB())) : libraryError;
+
    wxLogMessage(wxT("   Lib error: %s"), mpErrors->mLibraryError.Debug());
    printf("   Lib error: %s", mpErrors->mLibraryError.Debug().mb_str().data());
 }

src/DBConnection.h

@@ -31,6 +31,7 @@ struct DBConnectionErrors
 {
    TranslatableString mLastError;
    TranslatableString mLibraryError;
+   int mErrorCode { 0 };
 };
 
 class DBConnection
@@ -84,12 +85,14 @@ public:
    //! Just set stored errors
    void SetError(
       const TranslatableString &msg,
-      const TranslatableString &libraryError = {} );
+      const TranslatableString &libraryError = {}, 
+      int errorCode = {});
 
    //! Set stored errors and write to log; and default libraryError to what database library reports
    void SetDBError(
       const TranslatableString &msg,
-      const TranslatableString &libraryError = {} );
+      const TranslatableString& libraryError = {},
+      int errorCode = -1);
 
 private:
    bool ModeConfig(sqlite3 *db, const char *schema, const char *config);

src/ProjectFileIO.cpp

@@ -499,7 +499,8 @@ int ProjectFileIO::Exec(const char *query, const ExecCB &callback)
    {
       SetDBError(
          XO("Failed to execute a project file command:\n\n%s").Format(query),
-         Verbatim(errmsg)
+         Verbatim(errmsg),
+         rc
       );
    }
    if (errmsg)
@@ -596,6 +597,17 @@ bool ProjectFileIO::CheckVersion()
    wxString result;
    if (!GetValue("SELECT Count(*) FROM sqlite_master WHERE type='table';", result))
    {
+      // Bug 2718 workaround for a better error message:
+      // If at this point we get SQLITE_CANTOPEN, then the directory is read-only
+      if (GetLastErrorCode() == SQLITE_CANTOPEN)
+      {
+          SetError(
+              /* i18n-hint: An error message. */
+              XO("Project is in a read only directory\n(Unable to create the required temporary files)"),
+              GetLibraryError()
+          );
+      }
+
       return false;
    }
 
@@ -2170,30 +2182,35 @@ wxLongLong ProjectFileIO::GetFreeDiskSpace() const
    return -1;
 }
 
-const TranslatableString &ProjectFileIO::GetLastError()
+const TranslatableString &ProjectFileIO::GetLastError() const
 {
    return mpErrors->mLastError;
 }
 
-const TranslatableString &ProjectFileIO::GetLibraryError()
+const TranslatableString &ProjectFileIO::GetLibraryError() const
 {
    return mpErrors->mLibraryError;
 }
 
+int ProjectFileIO::GetLastErrorCode() const
+{
+    return mpErrors->mErrorCode;
+}
+
 void ProjectFileIO::SetError(
-   const TranslatableString &msg, const TranslatableString &libraryError )
+    const TranslatableString& msg, const TranslatableString& libraryError, int errorCode)
 {
    auto &currConn = CurrConn();
    if (currConn)
-      currConn->SetError(msg, libraryError);
+      currConn->SetError(msg, libraryError, errorCode);
 }
 
 void ProjectFileIO::SetDBError(
-   const TranslatableString &msg, const TranslatableString &libraryError)
+   const TranslatableString &msg, const TranslatableString &libraryError, int errorCode)
 {
    auto &currConn = CurrConn();
    if (currConn)
-      currConn->SetDBError(msg, libraryError);
+      currConn->SetDBError(msg, libraryError, errorCode);
 }
 
 void ProjectFileIO::SetBypass()

src/ProjectFileIO.h

@@ -114,8 +114,9 @@ public:
    // specific database. This is the workhorse for the above 3 methods.
    static int64_t GetDiskUsage(DBConnection &conn, SampleBlockID blockid);
 
-   const TranslatableString &GetLastError();
+   const TranslatableString &GetLastError() const;
-   const TranslatableString &GetLibraryError();
+   const TranslatableString &GetLibraryError() const;
+   int GetLastErrorCode() const;
 
    // Provides a means to bypass "DELETE"s at shutdown if the database
    // is just going to be deleted anyway.  This prevents a noticeable
@@ -256,11 +257,13 @@ private:
 
    //! Just set stored errors
    void SetError(const TranslatableString & msg,
-      const TranslatableString &libraryError = {});
+       const TranslatableString& libraryError = {},
+       int errorCode = {});
 
    //! Set stored errors and write to log; and default libraryError to what database library reports
    void SetDBError(const TranslatableString & msg,
-      const TranslatableString &libraryError = {});
+       const TranslatableString& libraryError = {},
+       int errorCode = -1);
 
    bool ShouldCompact(const std::vector<const TrackList *> &tracks);