Check last error after getting blob, before calling conversions (refs #…

…308)
gographics · Apr 3, 2024 · c0ff8ec · c0ff8ec
1 parent 54cc04d
commit c0ff8ec
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/imagick/magick_wand_image.go b/imagick/magick_wand_image.go
@@ -1125,6 +1125,9 @@ func (mw *MagickWand) GetImageBlob() []byte {
 	clen := C.size_t(0)
 	csblob := C.MagickGetImageBlob(mw.mw, &clen)
 	defer relinquishMemory(unsafe.Pointer(csblob))
+	if err := mw.GetLastError(); err != nil {
+		return nil
+	}
 	ret := C.GoBytes(unsafe.Pointer(csblob), C.int(clen))
 	runtime.KeepAlive(mw)
 	return ret
@@ -1140,6 +1143,9 @@ func (mw *MagickWand) GetImagesBlob() []byte {
 	clen := C.size_t(0)
 	csblob := C.MagickGetImagesBlob(mw.mw, &clen)
 	defer relinquishMemory(unsafe.Pointer(csblob))
+	if err := mw.GetLastError(); err != nil {
+		return nil
+	}
 	runtime.KeepAlive(mw)
 	return C.GoBytes(unsafe.Pointer(csblob), C.int(clen))
 }

diff --git a/imagick/magick_wand_test.go b/imagick/magick_wand_test.go
@@ -183,8 +183,14 @@ func TestReadImageBlob(t *testing.T) {
 
 	mw := NewMagickWand()
 
+	// Try to read an empty wand
+	blob := mw.GetImageBlob()
+	if blob != nil {
+		t.Fatal("Expected nil blob on invalid wand")
+	}
+
 	// Read an invalid blob
-	blob := []byte{}
+	blob = []byte{}
 	if err := mw.ReadImageBlob(blob); err == nil {
 		t.Fatal("Expected a failure when passing a zero length blob")
 	}