3 files changed, 50 insertions, 5 deletions

diff --git a/source/blender/alembic/intern/abc_archive.cc b/source/blender/alembic/intern/abc_archive.cc
index 5f8fc1a3739..cdbda0ace69 100644
--- a/source/blender/alembic/intern/abc_archive.cc
+++ b/source/blender/alembic/intern/abc_archive.cc
@@ -28,6 +28,8 @@
 #  include "utfconv.h"
 #endif
 
+#include <fstream>
+
 using Alembic::Abc::Exception;
 using Alembic::Abc::ErrorHandler;
 using Alembic::Abc::IArchive;
@@ -38,8 +40,9 @@ static IArchive open_archive(const std::string &filename,
                              const std::vector<std::istream *> &input_streams,
                              bool &is_hdf5)
 {
+	is_hdf5 = false;
+
 	try {
-		is_hdf5 = false;
 		Alembic::AbcCoreOgawa::ReadArchive archive_reader(input_streams);
 
 		return IArchive(archive_reader(filename),
@@ -63,6 +66,27 @@ static IArchive open_archive(const std::string &filename,
 			return IArchive();
 		}
 #else
+		/* Inspect the file to see whether it's really a HDF5 file. */
+		char header[4];  /* char(0x89) + "HDF" */
+		std::ifstream the_file(filename, std::ios::in | std::ios::binary);
+		if (!the_file) {
+			std::cerr << "Unable to open " << filename << std::endl;
+		}
+		else if (!the_file.read(header, sizeof(header))) {
+			std::cerr << "Unable to read from " << filename << std::endl;
+		}
+		else if (strncmp(header + 1, "HDF", 3)) {
+			std::cerr << filename << " has an unknown file format, unable to read." << std::endl;
+		}
+		else {
+			is_hdf5 = true;
+			std::cerr << filename << " is in the obsolete HDF5 format, unable to read." << std::endl;
+		}
+
+		if (the_file.is_open()) {
+			the_file.close();
+		}
+
 		return IArchive();
 #endif
 	}
@@ -83,16 +107,20 @@ ArchiveReader::ArchiveReader(const char *filename)
 
 	m_streams.push_back(&m_infile);
 
-	bool is_hdf5;
-	m_archive = open_archive(filename, m_streams, is_hdf5);
+	m_archive = open_archive(filename, m_streams, m_is_hdf5);
 
 	/* We can't open an HDF5 file from a stream, so close it. */
-	if (is_hdf5) {
+	if (m_is_hdf5) {
 		m_infile.close();
 		m_streams.clear();
 	}
 }
 
+bool ArchiveReader::is_hdf5() const
+{
+	return m_is_hdf5;
+}
+
 bool ArchiveReader::valid() const
 {
 	return m_archive.valid();
diff --git a/source/blender/alembic/intern/abc_archive.h b/source/blender/alembic/intern/abc_archive.h
index d412574b736..84309fbc9df 100644
--- a/source/blender/alembic/intern/abc_archive.h
+++ b/source/blender/alembic/intern/abc_archive.h
@@ -44,12 +44,21 @@ class ArchiveReader {
 	Alembic::Abc::IArchive m_archive;
 	std::ifstream m_infile;
 	std::vector<std::istream *> m_streams;
+	bool m_is_hdf5;
 
 public:
 	explicit ArchiveReader(const char *filename);
 
 	bool valid() const;
 
+	/**
+	 * Returns true when either Blender is compiled with HDF5 support and
+	 * the archive was succesfully opened (valid() will also return true),
+	 * or when Blender was built without HDF5 support but a HDF5 file was
+	 * detected (valid() will return false).
+	 */
+	bool is_hdf5() const;
+
 	Alembic::Abc::IObject getTop();
 };
 
diff --git a/source/blender/alembic/intern/alembic_capi.cc b/source/blender/alembic/intern/alembic_capi.cc
index e44f66b7e56..50e7626ad1e 100644
--- a/source/blender/alembic/intern/alembic_capi.cc
+++ b/source/blender/alembic/intern/alembic_capi.cc
@@ -595,6 +595,7 @@ static std::pair<bool, AbcObjectReader *> visit_object(
 enum {
 	ABC_NO_ERROR = 0,
 	ABC_ARCHIVE_FAIL,
+	ABC_UNSUPPORTED_HDF5,
 };
 
 struct ImportJobData {
@@ -659,8 +660,12 @@ static void import_startjob(void *user_data, short *stop, short *do_update, floa
 	ArchiveReader *archive = new ArchiveReader(data->filename);
 
 	if (!archive->valid()) {
-		delete archive;
+#ifndef WITH_ALEMBIC_HDF5
+		data->error_code = archive->is_hdf5() ? ABC_UNSUPPORTED_HDF5 : ABC_ARCHIVE_FAIL;
+#else
 		data->error_code = ABC_ARCHIVE_FAIL;
+#endif
+		delete archive;
 		return;
 	}
 
@@ -829,6 +834,9 @@ static void import_endjob(void *user_data)
 		case ABC_ARCHIVE_FAIL:
 			WM_report(RPT_ERROR, "Could not open Alembic archive for reading! See console for detail.");
 			break;
+		case ABC_UNSUPPORTED_HDF5:
+			WM_report(RPT_ERROR, "Alembic archive in obsolete HDF5 format is not supported.");
+			break;
 	}
 
 	WM_main_add_notifier(NC_SCENE | ND_FRAME, data->scene);