From f4cad429586c4904746b0b254fea8a92df5cdceb Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Thu, 13 Sep 2018 23:47:24 +0200
Subject: [PATCH] Lat-lon parsing: catch exceptions from std::stod

The standard library throws exceptions in some cases, catch those
and return false. Extend the test coverage for some of the problematic
cases.
---
 simgear/misc/strutils.cxx      | 75 ++++++++++++++++++----------------
 simgear/misc/strutils_test.cxx |  7 ++++
 2 files changed, 47 insertions(+), 35 deletions(-)

diff --git a/simgear/misc/strutils.cxx b/simgear/misc/strutils.cxx
index b15a73e7..88bf2d21 100644
--- a/simgear/misc/strutils.cxx
+++ b/simgear/misc/strutils.cxx
@@ -1136,44 +1136,49 @@ bool matchPropPathToTemplate(const std::string& path, const std::string& templat
  
 bool parseStringAsLatLonValue(const std::string& s, double& degrees)
 {
-    string ss = simplify(s);
-    auto spacePos = ss.find_first_of(" *");
-    
-    if (spacePos == std::string::npos) {
-        degrees = std::stod(ss);
-    } else {
-        degrees = std::stod(ss.substr(0, spacePos));
+    try {
+            string ss = simplify(s);
+            auto spacePos = ss.find_first_of(" *");
         
-        double minutes = 0.0, seconds = 0.0;
-        
-        // check for minutes marker
-        auto quotePos = ss.find('\'');
-        if (quotePos == std::string::npos) {
-            const auto minutesStr = ss.substr(spacePos+1);
-            if (!minutesStr.empty()) {
-                minutes = std::stod(minutesStr);
+            if (spacePos == std::string::npos) {
+                degrees = std::stod(ss);
+            } else {
+                degrees = std::stod(ss.substr(0, spacePos));
+                
+                double minutes = 0.0, seconds = 0.0;
+                
+                // check for minutes marker
+                auto quotePos = ss.find('\'');
+                if (quotePos == std::string::npos) {
+                    const auto minutesStr = ss.substr(spacePos+1);
+                    if (!minutesStr.empty()) {
+                        minutes = std::stod(minutesStr);
+                    }
+                } else {
+                    minutes = std::stod(ss.substr(spacePos+1, quotePos - spacePos));
+                    const auto secondsStr = ss.substr(quotePos+1);
+                    if (!secondsStr.empty()) {
+                        seconds = std::stod(secondsStr);
+                    }
+                }
+                
+                if ((seconds < 0.0) || (minutes < 0.0)) {
+                    // don't allow sign information in minutes or seconds
+                    return false;
+                }
+                
+                double offset = (minutes / 60.0) + (seconds / 3600.0);
+                degrees += (degrees >= 0.0) ? offset : -offset;
             }
-        } else {
-            minutes = std::stod(ss.substr(spacePos+1, quotePos - spacePos));
-            const auto secondsStr = ss.substr(quotePos+1);
-            if (!secondsStr.empty()) {
-                seconds = std::stod(secondsStr);
+        
+            // since we simplified, any trailing N/S/E/W must be the last char
+            const char lastChar = ::toupper(ss.back());
+            if ((lastChar == 'W') || (lastChar == 'S')) {
+                degrees = -degrees;
             }
-        }
-        
-        if ((seconds < 0.0) || (minutes < 0.0)) {
-            // don't allow sign information in minutes or seconds
-            return false;
-        }
-        
-        double offset = (minutes / 60.0) + (seconds / 3600.0);
-        degrees += (degrees >= 0.0) ? offset : -offset;
-    }
-    
-    // since we simplified, any trailing N/S/E/W must be the last char
-    const char lastChar = ::toupper(ss.back());
-    if ((lastChar == 'W') || (lastChar == 'S')) {
-        degrees = -degrees;
+    } catch (std::exception&) {
+        // std::stdo can throw
+        return false;
     }
     
     return true;
diff --git a/simgear/misc/strutils_test.cxx b/simgear/misc/strutils_test.cxx
index 35ac5b79..d9559ad3 100644
--- a/simgear/misc/strutils_test.cxx
+++ b/simgear/misc/strutils_test.cxx
@@ -676,6 +676,13 @@ void test_parseGeod()
     SG_VERIFY(strutils::parseStringAsGeod("\t40 30'50\"S,  12 34'56\"W ", &a, true));
     SG_CHECK_EQUAL_EP(a.getLongitudeDeg(), -12.58222222);
     SG_CHECK_EQUAL_EP(a.getLatitudeDeg(), -40.5138888);
+    
+    
+    // malformed inputs
+    
+    SG_VERIFY(strutils::parseStringAsGeod("12.345,", &a, true) == false);
+    double d;
+    SG_VERIFY(strutils::parseStringAsLatLonValue("", d) == false);
 }
 
 void test_formatGeod()