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List:       kde-i18n-doc
Subject:    [plasma-workspace/Plasma/5.8] runners/calculator: [Calculator Runner] Use "approximate" approximatio
From:       Kai Uwe Broulik <null () kde ! org>
Date:       2017-03-28 8:28:37
Message-ID: E1csmUX-0004Eq-Sj () code ! kde ! org
[Download RAW message or body]

Git commit 34b74d7b5dac9dd458a960e392954ac6c30df3d2 by Kai Uwe Broulik.
Committed on 28/03/2017 at 08:26.
Pushed by broulik into branch 'Plasma/5.8'.

[Calculator Runner] Use "approximate" approximation mode

The runner calculator isn't entitled for being a scientifically correct calculator.
This keeps seemingly innocent calculations such as "2^0.333333333" from eating all \
RAM until it crashes. A hint is added to the result if it is only an approximation.

BUG: 277011
FIXED-IN: 5.8.7
CCMAIL: kde-i18n-doc@kde.org

Differential Revision: https://phabricator.kde.org/D4290

(cherry picked from commit df7f1ed1eb7df7e3c039dc19db4893ca01b3327f)

M  +7    -3    runners/calculator/calculatorrunner.cpp
M  +1    -1    runners/calculator/calculatorrunner.h
M  +9    -1    runners/calculator/qalculate_engine.cpp
M  +1    -1    runners/calculator/qalculate_engine.h

https://commits.kde.org/plasma-workspace/34b74d7b5dac9dd458a960e392954ac6c30df3d2

diff --git a/runners/calculator/calculatorrunner.cpp \
b/runners/calculator/calculatorrunner.cpp index f9552d2f..86111c9e 100644
--- a/runners/calculator/calculatorrunner.cpp
+++ b/runners/calculator/calculatorrunner.cpp
@@ -258,7 +258,8 @@ void CalculatorRunner::match(Plasma::RunnerContext &context)
     cmd.replace(QRegExp(QStringLiteral("([a-zA-Z]+)")), QStringLiteral("Math.\\1")); \
//needed for accessing math funktions like sin(),....  #endif
 
-    QString result = calculate(cmd);
+    bool isApproximate = false;
+    QString result = calculate(cmd, &isApproximate);
     if (!result.isEmpty() && result != cmd) {
         if (toHex) {
             result = "0x" + QString::number(result.toInt(), 16).toUpper();
@@ -268,19 +269,22 @@ void CalculatorRunner::match(Plasma::RunnerContext &context)
         match.setType(Plasma::QueryMatch::InformationalMatch);
         match.setIconName(QStringLiteral("accessories-calculator"));
         match.setText(result);
+        if (isApproximate) {
+            match.setSubtext(i18nc("The result of the calculation is only an \
approximation", "Approximation")); +        }
         match.setData(result);
         match.setId(term);
         context.addMatch(match);
     }
 }
 
-QString CalculatorRunner::calculate(const QString& term)
+QString CalculatorRunner::calculate(const QString& term, bool *isApproximate)
 {
     #ifdef ENABLE_QALCULATE
     QString result;
 
     try {
-        result = m_engine->evaluate(term);
+        result = m_engine->evaluate(term, isApproximate);
     } catch(std::exception& e) {
         qDebug() << "qalculate error: " << e.what();
     }
diff --git a/runners/calculator/calculatorrunner.h \
b/runners/calculator/calculatorrunner.h index f14de4df..9ab1a860 100644
--- a/runners/calculator/calculatorrunner.h
+++ b/runners/calculator/calculatorrunner.h
@@ -47,7 +47,7 @@ class CalculatorRunner : public Plasma::AbstractRunner
         QMimeData * mimeDataForMatch(const Plasma::QueryMatch &match) override;
 
     private:
-        QString calculate(const QString& term);
+        QString calculate(const QString& term, bool *isApproximate);
         void userFriendlySubstitutions(QString& cmd);
         void powSubstitutions(QString& cmd);
         void hexSubstitutions(QString& cmd);
diff --git a/runners/calculator/qalculate_engine.cpp \
b/runners/calculator/qalculate_engine.cpp index f47cee78..39a3e672 100644
--- a/runners/calculator/qalculate_engine.cpp
+++ b/runners/calculator/qalculate_engine.cpp
@@ -79,7 +79,7 @@ void QalculateEngine::updateResult(KJob* job)
     }
 }
 
-QString QalculateEngine::evaluate(const QString& expression)
+QString QalculateEngine::evaluate(const QString& expression, bool *isApproximate)
 {
     if (expression.isEmpty()) {
         return "";
@@ -98,6 +98,10 @@ QString QalculateEngine::evaluate(const QString& expression)
     eo.parse_options.angle_unit = ANGLE_UNIT_RADIANS;
     eo.structuring = STRUCTURING_SIMPLIFY;
 
+    // suggested in https://github.com/Qalculate/libqalculate/issues/16
+    // to avoid memory overflow for seemingly innocent calculations (Bug 277011)
+    eo.approximation = APPROXIMATION_APPROXIMATE;
+
     CALCULATOR->setPrecision(16);
     MathStructure result = CALCULATOR->calculate(ctext, eo);
 
@@ -114,6 +118,10 @@ QString QalculateEngine::evaluate(const QString& expression)
 
     m_lastResult = result.print(po).c_str();
 
+    if (isApproximate) {
+        *isApproximate = result.isApproximate();
+    }
+
     return m_lastResult;
 }
 
diff --git a/runners/calculator/qalculate_engine.h \
b/runners/calculator/qalculate_engine.h index 5fd88876..5bdff27b 100644
--- a/runners/calculator/qalculate_engine.h
+++ b/runners/calculator/qalculate_engine.h
@@ -35,7 +35,7 @@ public:
 	QString lastResult() const { return m_lastResult; }
 
 public Q_SLOTS:
-	QString evaluate(const QString& expression);
+    QString evaluate(const QString& expression, bool *isApproximate = nullptr);
 	void updateExchangeRates();
 
 	void copyToClipboard(bool flag = true);


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