Add QUtil::make_shared_cstr

Replace most of the calls to QUtil::copy_string with this instead.

3 files changed, 18 insertions, 7 deletions

diff --git a/libqpdf/QPDFWriter.cc b/libqpdf/QPDFWriter.cc
index e7fb9ad6..c0ee68d1 100644
--- a/libqpdf/QPDFWriter.cc
+++ b/libqpdf/QPDFWriter.cc
@@ -1915,9 +1915,8 @@ QPDFWriter::unparseObject(QPDFObjectHandle object, int level,
 	    }
 	    else
 	    {
-		PointerHolder<char> tmp_ph =
-                    PointerHolder<char>(true, QUtil::copy_string(val));
-                char* tmp = tmp_ph.getPointer();
+		auto tmp_ph = QUtil::make_shared_cstr(val);
+                char* tmp = tmp_ph.get();
 		size_t vlen = val.length();
 		RC4 rc4(QUtil::unsigned_char_pointer(this->m->cur_data_key),
 			QIntC::to_int(this->m->cur_data_key.length()));
diff --git a/libqpdf/QPDF_encryption.cc b/libqpdf/QPDF_encryption.cc
index 9607a598..d5289ad3 100644
--- a/libqpdf/QPDF_encryption.cc
+++ b/libqpdf/QPDF_encryption.cc
@@ -1211,10 +1211,10 @@ QPDF::decryptString(std::string& str, int objid, int generation)
 	    size_t vlen = str.length();
 	    // Using PointerHolder guarantees that tmp will
 	    // be freed even if rc4.process throws an exception.
-	    PointerHolder<char> tmp(true, QUtil::copy_string(str));
+	    auto tmp = QUtil::make_shared_cstr(str);
 	    RC4 rc4(QUtil::unsigned_char_pointer(key), toI(key.length()));
-	    rc4.process(QUtil::unsigned_char_pointer(tmp.getPointer()), vlen);
-	    str = std::string(tmp.getPointer(), vlen);
+	    rc4.process(QUtil::unsigned_char_pointer(tmp.get()), vlen);
+	    str = std::string(tmp.get(), vlen);
 	}
     }
     catch (QPDFExc&)
diff --git a/libqpdf/QUtil.cc b/libqpdf/QUtil.cc
index c71e7923..cfd1bb1e 100644
--- a/libqpdf/QUtil.cc
+++ b/libqpdf/QUtil.cc
@@ -731,6 +731,18 @@ QUtil::copy_string(std::string const& str)
     return result;
 }
 
+std::shared_ptr<char>
+QUtil::make_shared_cstr(std::string const& str)
+{
+    auto result = std::shared_ptr<char>(
+        new char[str.length() + 1],
+        std::default_delete<char[]>());
+    // Use memcpy in case string contains nulls
+    result.get()[str.length()] = '\0';
+    memcpy(result.get(), str.c_str(), str.length());
+    return result;
+}
+
 std::string
 QUtil::hex_encode(std::string const& input)
 {
@@ -2625,7 +2637,7 @@ QUtil::call_main_from_wmain(int argc, wchar_t* argv[],
                              QIntC::to_uchar(codepoint & 0xff)));
         }
         std::string utf8 = QUtil::utf16_to_utf8(utf16);
-        utf8_argv.push_back(std::shared_ptr<char>(QUtil::copy_string(utf8.c_str()), std::default_delete<char[]>()));
+        utf8_argv.push_back(QUtil::make_shared_cstr(utf8));
     }
     auto utf8_argv_sp =
         std::shared_ptr<char*>(new char*[1+utf8_argv.size()], std::default_delete<char*[]>());