YAML: refactor YAML-exception reporting

- both NetInstall (group data) and Locale (GeoIP) use network
   data returned as a source of YAML data. Try to explain
   parsing errors for both.

FIXES #786

src/libcalamaresui/utils/YamlUtils.cpp

@@ -18,8 +18,11 @@
  */
 #include "YamlUtils.h"
 
+#include "utils/Logger.h"
+
 #include <yaml-cpp/yaml.h>
 
+#include <QByteArray>
 #include <QRegExp>
 
 void
@@ -105,4 +108,42 @@ yamlMapToVariant( const YAML::Node& mapNode )
 }
 
 
+void
+explainYamlException( const YAML::Exception& e, const QByteArray& yamlData, const char *label )
+{
+    cDebug() << "WARNING: YAML error " << e.what() << "in" << label << '.';
+    if ( ( e.mark.line >= 0 ) && ( e.mark.column >= 0 ) )
+    {
+        // Try to show the line where it happened.
+        int linestart = 0;
+        for ( int linecount = 0; linecount < e.mark.line; ++linecount )
+        {
+            linestart = yamlData.indexOf( '\n', linestart );
+            // No more \ns found, weird
+            if ( linestart < 0 )
+                break;
+            linestart += 1;  // Skip that \n
+        }
+        int lineend = linestart;
+        if ( linestart >= 0 )
+        {
+            lineend = yamlData.indexOf( '\n', linestart );
+            if ( lineend < 0 )
+                lineend = yamlData.length();
+        }
+
+        int rangestart = linestart;
+        int rangeend = lineend;
+        // Adjust range (linestart..lineend) so it's not too long
+        if ( ( linestart >= 0 ) && ( e.mark.column > 30 ) )
+            rangestart += ( e.mark.column - 30 );
+        if ( ( linestart >= 0 ) && ( rangeend - rangestart > 40 ) )
+            rangeend = rangestart + 40;
+
+        if ( linestart >= 0 )
+            cDebug() << "WARNING: offending YAML data:" << yamlData.mid( rangestart, rangeend-rangestart ).constData();
+
+    }
 }
+
+}  // namespace

src/libcalamaresui/utils/YamlUtils.h

@@ -1,6 +1,7 @@
 /* === This file is part of Calamares - <http://github.com/calamares> ===
  *
  *   Copyright 2014, Teo Mrnjavac <teo@kde.org>
+ *   Copyright 2017, Adriaan de Groot <groot@kde.org>
  *
  *   Calamares is free software: you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -22,9 +23,12 @@
 #include <QStringList>
 #include <QVariant>
 
+class QByteArray;
+
 namespace YAML
 {
 class Node;
+class Exception;
 }
 
 void operator>>( const YAML::Node& node, QStringList& v );
@@ -37,6 +41,13 @@ QVariant yamlScalarToVariant( const YAML::Node& scalarNode );
 QVariant yamlSequenceToVariant( const YAML::Node& sequenceNode );
 QVariant yamlMapToVariant( const YAML::Node& mapNode );
 
+/**
+ * Given an exception from the YAML parser library, explain
+ * what is going on in terms of the data passed to the parser.
+ * Uses @p label when labeling the data source (e.g. "netinstall data")
+ */
+void explainYamlException( const YAML::Exception& e, const QByteArray& data, const char *label );
+
 } //ns
 
 #endif // YAMLUTILS_H

src/modules/locale/LocaleViewStep.cpp

@@ -115,6 +115,10 @@ LocaleViewStep::fetchGeoIpTimezone()
             [=]( QNetworkReply* reply )
     {
         if ( reply->error() == QNetworkReply::NoError )
+        {
+            QByteArray data = reply->readAll();
+
+            try
             {
                 YAML::Node doc = YAML::Load( reply->readAll() );
 
@@ -139,6 +143,11 @@ LocaleViewStep::fetchGeoIpTimezone()
                     }
                 }
             }
+            catch ( YAML::Exception& e )
+            {
+                CalamaresUtils::explainYamlException( e, data, "GeoIP data");
+            }
+        }
 
         reply->deleteLater();
         manager->deleteLater();

src/modules/netinstall/NetInstallPage.cpp

@@ -83,38 +83,7 @@ NetInstallPage::readGroups( const QByteArray& yamlData )
     }
     catch ( YAML::Exception& e )
     {
-        cDebug() << "WARNING: YAML error " << e.what() << "in netinstall groups data.";
-        if ( ( e.mark.line >= 0 ) && ( e.mark.column >= 0 ) )
-        {
-            // Try to show the line where it happened.
-            int linestart = 0;
-            for ( int linecount = 0; linecount < e.mark.line; ++linecount )
-            {
-                linestart = yamlData.indexOf( '\n', linestart );
-                // No more \ns found, weird
-                if ( linestart < 0 )
-                    break;
-                linestart += 1;  // Skip that \n
-            }
-            int lineend = linestart;
-            if ( linestart >= 0 )
-            {
-                lineend = yamlData.indexOf( '\n', linestart );
-                if ( lineend < 0 )
-                    lineend = yamlData.length();
-            }
-
-            int rangestart = linestart;
-            int rangeend = lineend;
-            // Adjust range (linestart..lineend) so it's not too long
-            if ( ( linestart >= 0 ) && ( e.mark.column > 30 ) )
-                rangestart += ( e.mark.column - 30 );
-            if ( ( linestart >= 0 ) && ( rangeend - rangestart > 40 ) )
-                rangeend = rangestart + 40;
-
-            if ( linestart >= 0 )
-                cDebug() << "WARNING: offending YAML data:" << yamlData.mid( rangestart, rangeend-rangestart ).constData();
-        }
+        CalamaresUtils::explainYamlException( e, yamlData, "netinstall groups data" );
         return false;
     }
 }