Detect recoverable but invalid zlib data streams (fixes #562)

3 files changed, 21 insertions, 2 deletions

diff --git a/zlib-flate/qtest/missing-z-finish.in b/zlib-flate/qtest/missing-z-finish.in
new file mode 100644
index 00000000..848c9c5c
--- /dev/null
+++ b/zlib-flate/qtest/missing-z-finish.in
@@ -0,0 +1,2 @@
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	rM*N��4202i3614�25�20�60�I%E�Ff&�� Nr�[����kRr>�I��)�

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\ No newline at end of file
diff --git a/zlib-flate/qtest/zf.test b/zlib-flate/qtest/zf.test
index 2b188eb2..2f89ff54 100644
--- a/zlib-flate/qtest/zf.test
+++ b/zlib-flate/qtest/zf.test
@@ -29,4 +29,11 @@ $td->runtest("error",
 	      $td->EXIT_STATUS => 2},
 	     $td->NORMALIZE_NEWLINES);
 
-$td->report(7);
+$td->runtest("corrupted input",
+	     {$td->COMMAND => "zlib-flate -uncompress < missing-z-finish.in"},
+	     {$td->REGEXP =>
+                  "input stream is complete but output may still be valid",
+                  $td->EXIT_STATUS => 3},
+	     $td->NORMALIZE_NEWLINES);
+
+$td->report(8);
diff --git a/zlib-flate/zlib-flate.cc b/zlib-flate/zlib-flate.cc
index 4d65bcc3..ae0fa4e1 100644
--- a/zlib-flate/zlib-flate.cc
+++ b/zlib-flate/zlib-flate.cc
@@ -76,6 +76,12 @@ int main(int argc, char* argv[])
     PointerHolder<Pl_StdioFile> out = new Pl_StdioFile("stdout", stdout);
     PointerHolder<Pl_Flate> flate =
         new Pl_Flate("flate", out.getPointer(), action);
+    bool warn = false;
+    flate->setWarnCallback([&warn](char const* msg, int code) {
+        warn = true;
+        std::cerr << whoami << ": WARNING: zlib code " << code
+                  << ", msg = " << msg << std::endl;
+    });
 
     try
     {
@@ -97,9 +103,13 @@ int main(int argc, char* argv[])
     }
     catch (std::exception& e)
     {
-	std::cerr << e.what() << std::endl;
+	std::cerr << whoami << ": " << e.what() << std::endl;
 	exit(2);
     }
 
+    if (warn)
+    {
+        exit(3);
+    }
     return 0;
 }