Add Python error handling to video_images_getHEADmaster

If for any reason the data stream from the camera is no longer
available, without these checks the entire python interpreter crashes
with a nice segmentation fault.

These checks allow to handle the error from within Python with something
like:

    try:
        o3000.video_images_get()
    except RuntimeError:
        ... restart o3000 driver

Also, there is a change in the compilation flags to show more (useful)
warnings, i.e. -Wall and hide the "unused variable" warning.

2 files changed, 18 insertions, 5 deletions

diff --git a/c_extension.c b/c_extension.c
index 7aebced..d2e7e4e 100644
--- a/c_extension.c
+++ b/c_extension.c
@@ -328,16 +328,28 @@ _abort_video_main1:
 
 static PyObject* video_images_get(PyObject* self, PyObject* args) {
 	
-	npy_intp dims[3];
+	if (!recthread_data_recent) {
+		// fprintf(stderr, "%s: no data from video thread", __func__);
+		PyErr_SetString(PyExc_RuntimeError, "No data from video thread");
+		return NULL;
+	}
 	
 	struct color_pipe_t *cp = recthread_data_recent->color_pipe;
-	
+
+	if (!cp) {
+		// fprintf(stderr, "%s: cannot read color pipeline\n", __func__);
+		PyErr_SetString(PyExc_RuntimeError, "Cannot read color pipeline");
+		return NULL;
+	}
 	
 	if (!is_color) {
-		fprintf(stderr, "%s: not implemented for gray images\n", __func__);
+		// fprintf(stderr, "%s: not implemented for gray images\n", __func__);
+		PyErr_SetString(PyExc_RuntimeError, "Not implemented for gray images");
 		return NULL;
 	}
 	
+	npy_intp dims[3];
+
 	dims[0] = cp->height;
 	dims[1] = cp->width;
 	dims[2] = 3;
@@ -388,7 +400,7 @@ static PyObject* video_deinit(PyObject* self, PyObject* args) {
 
 static PyObject* video_xml_send(PyObject* self, PyObject* args) {
 	Py_ssize_t count;
-	const uint8_t* str;
+	const char* str;
 	if (!PyArg_ParseTuple(args, "s#", &str, &count)) {
 		return NULL;
 	}
@@ -421,3 +433,4 @@ PyMODINIT_FUNC PyInit_o3000(void) {
 	_import_array();
 	return PyModule_Create(&o3000);
 }
+
diff --git a/setup_c_extension.py b/setup_c_extension.py
index e01837f..f1f3e08 100644
--- a/setup_c_extension.py
+++ b/setup_c_extension.py
@@ -12,5 +12,5 @@ setup(name = 'o3000', version = '1.0',
 				sources = ['c_extension.c', 'helpers.c'],
 				libraries = ['o3000', 'o3000_imgpipe', 'tiff'],
 				include_dirs = [str(numpy_headers_path)],
-				# extra_compile_args = ['-Wextra']
+				extra_compile_args = ['-Wextra', '-Wall', '-Wno-unused-parameter']
 		)])