From a2f62935b35aebe68a5a2f7e729ae4bb8734cfc7 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Sun, 12 Aug 2018 21:57:52 -0400
Subject: [PATCH] Catch exceptions as const references (fixes #236)

This fix allows qpdf to compile/test cleanly with gcc 8.
---
 examples/pdf-split-pages.cc |  2 +-
 libqpdf/MD5.cc              |  2 +-
 libtests/qutil.cc           |  4 ++--
 qpdf/qpdf.cc                |  4 ++--
 qpdf/test_driver.cc         | 16 ++++++++--------
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/examples/pdf-split-pages.cc b/examples/pdf-split-pages.cc
index b65f96ee..aa089e5a 100644
--- a/examples/pdf-split-pages.cc
+++ b/examples/pdf-split-pages.cc
@@ -77,7 +77,7 @@ int main(int argc, char* argv[])
     {
         process(whoami, argv[1], argv[2]);
     }
-    catch (std::exception e)
+    catch (std::exception const& e)
     {
         std::cerr << whoami << ": exception: " << e.what() << std::endl;
         return 2;
diff --git a/libqpdf/MD5.cc b/libqpdf/MD5.cc
index 0504e2d4..275567da 100644
--- a/libqpdf/MD5.cc
+++ b/libqpdf/MD5.cc
@@ -421,7 +421,7 @@ MD5::checkFileChecksum(char const* const checksum,
 	std::string actual_checksum = getFileChecksum(filename, up_to_size);
 	result = (checksum == actual_checksum);
     }
-    catch (std::runtime_error)
+    catch (std::runtime_error const&)
     {
 	// Ignore -- return false
     }
diff --git a/libtests/qutil.cc b/libtests/qutil.cc
index a7479fb5..78c52156 100644
--- a/libtests/qutil.cc
+++ b/libtests/qutil.cc
@@ -26,7 +26,7 @@ void test_to_number(char const* str, int_T wanted, bool error,
         result = fn(str);
         worked = (wanted == result);
     }
-    catch (std::runtime_error)
+    catch (std::runtime_error const&)
     {
         threw = true;
     }
@@ -247,7 +247,7 @@ void same_file_test()
         fclose(QUtil::safe_fopen("qutil.out", "r"));
         fclose(QUtil::safe_fopen("other-file", "r"));
     }
-    catch (std::exception)
+    catch (std::exception const&)
     {
         std::cout << "same_file_test expects to have qutil.out and other-file"
             " exist in the current directory\n";
diff --git a/qpdf/qpdf.cc b/qpdf/qpdf.cc
index 9655049f..158bb993 100644
--- a/qpdf/qpdf.cc
+++ b/qpdf/qpdf.cc
@@ -773,7 +773,7 @@ static std::vector<int> parse_numrange(char const* range, int max,
             }
         }
     }
-    catch (std::runtime_error e)
+    catch (std::runtime_error const& e)
     {
         if (throw_error)
         {
@@ -1372,7 +1372,7 @@ static void parse_rotation_parameter(Options& o, std::string const& parameter)
         parse_numrange(range.c_str(), 0, true);
         range_valid = true;
     }
-    catch (std::runtime_error)
+    catch (std::runtime_error const&)
     {
         // ignore
     }
diff --git a/qpdf/test_driver.cc b/qpdf/test_driver.cc
index c167b643..14a317ba 100644
--- a/qpdf/test_driver.cc
+++ b/qpdf/test_driver.cc
@@ -717,7 +717,7 @@ void runtest(int n, char const* filename1, char const* arg2)
 	    // Do it wrong first...
 	    pdf.replaceObject(qdict.getObjGen(), qdict);
 	}
-	catch (std::logic_error)
+	catch (std::logic_error const&)
 	{
 	    std::cout << "caught logic error as expected" << std::endl;
 	}
@@ -1003,7 +1003,7 @@ void runtest(int n, char const* filename1, char const* arg2)
             res2.unparseResolved();
             std::cout << "oops -- didn't throw" << std::endl;
         }
-        catch (std::logic_error e)
+        catch (std::logic_error const& e)
         {
             std::cout << "logic error: " << e.what() << std::endl;
         }
@@ -1012,7 +1012,7 @@ void runtest(int n, char const* filename1, char const* arg2)
             res2.makeDirect();
             std::cout << "oops -- didn't throw" << std::endl;
         }
-        catch (std::logic_error e)
+        catch (std::logic_error const& e)
         {
             std::cout << "logic error: " << e.what() << std::endl;
         }
@@ -1109,7 +1109,7 @@ void runtest(int n, char const* filename1, char const* arg2)
             pdf.copyForeignObject(pdf.getTrailer().getKey("/QTest"));
             std::cout << "oops -- didn't throw" << std::endl;
         }
-        catch (std::logic_error e)
+        catch (std::logic_error const& e)
         {
             std::cout << "logic error: " << e.what() << std::endl;
         }
@@ -1118,7 +1118,7 @@ void runtest(int n, char const* filename1, char const* arg2)
             pdf.copyForeignObject(QPDFObjectHandle::newInteger(1));
             std::cout << "oops -- didn't throw" << std::endl;
         }
-        catch (std::logic_error e)
+        catch (std::logic_error const& e)
         {
             std::cout << "logic error: " << e.what() << std::endl;
         }
@@ -1139,7 +1139,7 @@ void runtest(int n, char const* filename1, char const* arg2)
             w.write();
             std::cout << "oops -- didn't throw" << std::endl;
         }
-        catch (std::logic_error e)
+        catch (std::logic_error const& e)
         {
             std::cout << "logic error: " << e.what() << std::endl;
         }
@@ -1185,7 +1185,7 @@ void runtest(int n, char const* filename1, char const* arg2)
             QPDFObjectHandle::parse("[1 0 R]", "indirect test");
             std::cout << "oops -- didn't throw" << std::endl;
         }
-        catch (std::logic_error e)
+        catch (std::logic_error const& e)
         {
             std::cout << "logic error parsing indirect: " << e.what()
                       << std::endl;
@@ -1195,7 +1195,7 @@ void runtest(int n, char const* filename1, char const* arg2)
             QPDFObjectHandle::parse("0 trailing", "trailing test");
             std::cout << "oops -- didn't throw" << std::endl;
         }
-        catch (std::runtime_error e)
+        catch (std::runtime_error const& e)
         {
             std::cout << "trailing data: " << e.what()
                       << std::endl;