Fix segmentation fault with use of QPDFWriter::setOutputMemory

2 files changed, 22 insertions, 12 deletions

diff --git a/qpdf/qtest/qpdf.test b/qpdf/qtest/qpdf.test
index fda92b30..b2ee28eb 100644
--- a/qpdf/qtest/qpdf.test
+++ b/qpdf/qtest/qpdf.test
@@ -149,7 +149,7 @@ $td->runtest("remove page we don't have",
 	     $td->NORMALIZE_NEWLINES);
 # ----------
 $td->notify("--- Miscellaneous Tests ---");
-$n_tests += 47;
+$n_tests += 48;
 
 $td->runtest("qpdf version",
 	     {$td->COMMAND => "qpdf --version"},
@@ -322,6 +322,11 @@ $td->runtest("swap and replace",
 $td->runtest("check output",
 	     {$td->FILE => "a.pdf"},
 	     {$td->FILE => "test14-out.pdf"});
+# Test 14 also exercises writing to memory without static ID.
+$td->runtest("check non-static ID version",
+             {$td->COMMAND => "./diff-ignore-ID-version a.pdf b.pdf"},
+             {$td->STRING => "okay\n", $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
 
 $td->runtest("C API info key functions",
 	     {$td->COMMAND => "qpdf-ctest 16 minimal.pdf '' a.pdf"},
diff --git a/qpdf/test_driver.cc b/qpdf/test_driver.cc
index 3861c403..b277cdf1 100644
--- a/qpdf/test_driver.cc
+++ b/qpdf/test_driver.cc
@@ -646,17 +646,22 @@ void runtest(int n, char const* filename1, char const* filename2)
 	}
 
 	// Exercise writing to memory buffer
-	QPDFWriter w(pdf);
-	w.setOutputMemory();
-	w.setStaticID(true);
-	w.setStreamDataMode(qpdf_s_preserve);
-	w.write();
-	Buffer* b = w.getBuffer();
-	FILE* f = QUtil::fopen_wrapper(std::string("open a.pdf"),
-				       fopen("a.pdf", "wb"));
-	fwrite(b->getBuffer(), b->getSize(), 1, f);
-	fclose(f);
-	delete b;
+        for (int i = 0; i < 2; ++i)
+        {
+            QPDFWriter w(pdf);
+            w.setOutputMemory();
+            // Exercise setOutputMemory with and without static ID
+            w.setStaticID(i == 0);
+            w.setStreamDataMode(qpdf_s_preserve);
+            w.write();
+            Buffer* b = w.getBuffer();
+            std::string const filename = (i == 0 ? "a.pdf" : "b.pdf");
+            FILE* f = QUtil::fopen_wrapper("open " + filename,
+                                           fopen(filename.c_str(), "wb"));
+            fwrite(b->getBuffer(), b->getSize(), 1, f);
+            fclose(f);
+            delete b;
+        }
     }
     else if (n == 15)
     {