From 24c1272cf4397614fb7ea5502bba9258e6a8f972 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Sun, 3 Feb 2019 14:48:17 +0100
Subject: WKT1 export: avoid division by zero. Fixes
 https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=12854. Credit to OSS
 Fuzz

---
 src/iso19111/common.cpp              | 15 ++++++++-------
 src/iso19111/coordinateoperation.cpp | 16 ++++++++++++----
 2 files changed, 20 insertions(+), 11 deletions(-)

(limited to 'src')

diff --git a/src/iso19111/common.cpp b/src/iso19111/common.cpp
index 57654d84..bdd836e1 100644
--- a/src/iso19111/common.cpp
+++ b/src/iso19111/common.cpp
@@ -172,21 +172,22 @@ void UnitOfMeasure::_exportToWKT(
 {
     const bool isWKT2 = formatter->version() == WKTFormatter::Version::WKT2;
 
-    if (formatter->forceUNITKeyword() && type() != Type::PARAMETRIC) {
+    const auto l_type = type();
+    if (formatter->forceUNITKeyword() && l_type != Type::PARAMETRIC) {
         formatter->startNode(WKTConstants::UNIT, !codeSpace().empty());
     } else if (!unitType.empty()) {
         formatter->startNode(unitType, !codeSpace().empty());
     } else {
-        if (isWKT2 && type() == Type::LINEAR) {
+        if (isWKT2 && l_type == Type::LINEAR) {
             formatter->startNode(WKTConstants::LENGTHUNIT,
                                  !codeSpace().empty());
-        } else if (isWKT2 && type() == Type::ANGULAR) {
+        } else if (isWKT2 && l_type == Type::ANGULAR) {
             formatter->startNode(WKTConstants::ANGLEUNIT, !codeSpace().empty());
-        } else if (isWKT2 && type() == Type::SCALE) {
+        } else if (isWKT2 && l_type == Type::SCALE) {
             formatter->startNode(WKTConstants::SCALEUNIT, !codeSpace().empty());
-        } else if (isWKT2 && type() == Type::TIME) {
+        } else if (isWKT2 && l_type == Type::TIME) {
             formatter->startNode(WKTConstants::TIMEUNIT, !codeSpace().empty());
-        } else if (isWKT2 && type() == Type::PARAMETRIC) {
+        } else if (isWKT2 && l_type == Type::PARAMETRIC) {
             formatter->startNode(WKTConstants::PARAMETRICUNIT,
                                  !codeSpace().empty());
         } else {
@@ -211,7 +212,7 @@ void UnitOfMeasure::_exportToWKT(
             formatter->addQuotedString(l_name);
         }
         const auto &factor = conversionToSI();
-        if (!isWKT2 || factor != 0.0) {
+        if (!isWKT2 || l_type != Type::TIME || factor != 0.0) {
             // Some TIMEUNIT do not have a conversion factor
             formatter->add(factor);
         }
diff --git a/src/iso19111/coordinateoperation.cpp b/src/iso19111/coordinateoperation.cpp
index 6f9b6283..8a10bc5a 100644
--- a/src/iso19111/coordinateoperation.cpp
+++ b/src/iso19111/coordinateoperation.cpp
@@ -2147,11 +2147,19 @@ void ParameterValue::_exportToWKT(io::WKTFormatter *formatter) const {
             // registered linear / angular unit.
             const auto &unitType = unit.type();
             if (unitType == common::UnitOfMeasure::Type::LINEAR) {
-                formatter->add(
-                    l_value.convertToUnit(*(formatter->axisLinearUnit())));
+                const auto &targetUnit = *(formatter->axisLinearUnit());
+                if (targetUnit.conversionToSI() == 0.0) {
+                    throw io::FormattingException(
+                        "cannot convert value to target linear unit");
+                }
+                formatter->add(l_value.convertToUnit(targetUnit));
             } else if (unitType == common::UnitOfMeasure::Type::ANGULAR) {
-                formatter->add(
-                    l_value.convertToUnit(*(formatter->axisAngularUnit())));
+                const auto &targetUnit = *(formatter->axisAngularUnit());
+                if (targetUnit.conversionToSI() == 0.0) {
+                    throw io::FormattingException(
+                        "cannot convert value to target angular unit");
+                }
+                formatter->add(l_value.convertToUnit(targetUnit));
             } else {
                 formatter->add(l_value.getSIValue());
             }
-- 
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