TgaImporter: check if the file is long enough.

Prevents undefined behavior when opening e.g. empty files.

src/Plugins/TgaImporter/Test/TgaImporterTest.cpp

@@ -36,6 +36,18 @@ void TgaImporterTest::openInexistent() {
     QCOMPARE(debug.str().c_str(), "TgaImporter: cannot open file inexistent.file\n");
 }
 
+void TgaImporterTest::openShort() {
+    const char data[] = { 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+    istringstream in(string(data, sizeof(data)));
+
+    ostringstream debug;
+    Error::setOutput(&debug);
+
+    TgaImporter importer;
+    QVERIFY(!importer.open(in));
+    QCOMPARE(debug.str().c_str(), "TgaImporter: the file is too short: 17 bytes\n");
+}
+
 void TgaImporterTest::paletted() {
     const char data[] = { 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
     istringstream in(string(data, sizeof(data)));

src/Plugins/TgaImporter/Test/TgaImporterTest.h

@@ -24,6 +24,7 @@ class TgaImporterTest: public QObject {
 
     private slots:
         void openInexistent();
+        void openShort();
         void paletted();
         void nonRgb();
         void bits16();

src/Plugins/TgaImporter/TgaImporter.cpp

@@ -47,6 +47,15 @@ bool TgaImporter::open(std::istream& in) {
         return false;
     }
 
+    /* Check if the file is long enough */
+    in.seekg(0, istream::end);
+    streampos filesize = in.tellg();
+    in.seekg(0, istream::beg);
+    if(filesize < streampos(sizeof(Header))) {
+        Error() << "TgaImporter: the file is too short:" << filesize << "bytes";
+        return false;
+    }
+
     Header header;
     in.read(reinterpret_cast<char*>(&header), sizeof(Header));