Merge pull request #191 from ctabin/fix-zero-file-read

Fixes read of zero-file length
ctabin · Apr 29, 2023 · 8b7a1fc · 8b7a1fc
2 parents c65d0b0 + 854fb7a
commit 8b7a1fc
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Showing 2 changed files with 17 additions and 4 deletions.
diff --git a/src/libzippp.cpp b/src/libzippp.cpp
@@ -905,7 +905,7 @@ int ZipArchive::readEntry(const ZipEntry& zipEntry, std::function<bool(const voi
             char* data = NEW_CHAR_ARRAY(maxSize)
             if (data!=nullptr) {
                 libzippp_int64 result = zip_fread(zipFile, data, maxSize);
-                if (result>0) {
+                if (result>=0) {
                     if (result != static_cast<libzippp_int64>(maxSize)) {
                         iRes = LIBZIPPP_ERROR_OWRITE_INDEX_FAILURE;
                     } else if (!writeFunc(data, maxSize)) {
@@ -926,7 +926,7 @@ int ZipArchive::readEntry(const ZipEntry& zipEntry, std::function<bool(const voi
                 string::size_type nbChunks = maxSize/chunksize;
                 for (libzippp_uint32 uiChunk=0 ; uiChunk<nbChunks ; ++uiChunk) {
                     result = zip_fread(zipFile, data, chunksize);
-                    if (result>0) {
+                    if (result>=0) {
                         if (result!=static_cast<libzippp_int64>(chunksize)) {
                             iRes = LIBZIPPP_ERROR_OWRITE_INDEX_FAILURE;
                             break;
@@ -952,7 +952,7 @@ int ZipArchive::readEntry(const ZipEntry& zipEntry, std::function<bool(const voi
                 char* data = NEW_CHAR_ARRAY(leftOver);
                 if (data!=nullptr) {
                     result = zip_fread(zipFile, data, leftOver);
-                    if (result>0) {
+                    if (result>=0) {
                         if (result!=static_cast<libzippp_int64>(leftOver)) {
                             iRes = LIBZIPPP_ERROR_OWRITE_INDEX_FAILURE;
                         } else {

diff --git a/tests/tests.cpp b/tests/tests.cpp
@@ -566,12 +566,14 @@ void test19() {
     ZipArchive z1("test.zip");
     z1.open(ZipArchive::Write);
     z1.addData("somedata", txtFile, len);
+    z1.addData("emptydata", "", 0);
     z1.close();
 
     ZipArchive z2("test.zip");
     z2.open(ZipArchive::ReadOnly);
-    assert(z2.getNbEntries()==1);
+    assert(z2.getNbEntries()==2);
     assert(z2.hasEntry("somedata"));
+    assert(z2.hasEntry("emptydata"));
 
     ZipEntry entry = z2.getEntry("somedata");
     assert(!entry.isNull());
@@ -591,6 +593,17 @@ void test19() {
     assert(clen3==len);
     assert(strncmp("this is some data", data3.c_str(), len)==0);
 
+    ZipEntry entry2 = z2.getEntry("emptydata");
+    assert(!entry2.isNull());
+
+    std::ofstream file;
+    file.open("empty", std::ios_base::out | std::ios_base::binary);
+    int ret = z2.readEntry(entry2, file);
+    assert(ret == LIBZIPPP_OK);
+    assert(file.tellp() == 0);
+    file.close();
+    remove("empty");
+
     z2.close();
     z2.unlink();