From: Martin Atkins <redacted>
Date: Sun, 25 Oct 2020 20:16:37 +0000 (-0700)
Subject: scpi-pps: Data capture dynamically-probed channels
X-Git-Url: http://sigrok.org/gitweb/?a=commitdiff_plain;h=c54b3726418c8211bf9cb19323b5ba09ad409e1c;p=libsigrok.git

scpi-pps: Data capture dynamically-probed channels

For the few device profiles that probe the device dynamically to determine
channel settings, the results end up in the dynamically-allocated
devc->channels instead of in the statically-configured
devc->device->channels field.

Previously this would crash by dereferencing a null ch_spec for the
device types that do dynamic channel configuration.

[ gsi: address minor style nits ]
---

diff --git a/src/hardware/scpi-pps/protocol.c b/src/hardware/scpi-pps/protocol.c
index 9609936a..825fdb94 100644
--- a/src/hardware/scpi-pps/protocol.c
+++ b/src/hardware/scpi-pps/protocol.c
@@ -97,7 +97,13 @@ SR_PRIV int scpi_pps_receive_data(int fd, int revents, void *cb_data)
 	if (ret != SR_OK)
 		return ret;
 
-	ch_spec = &devc->device->channels[pch->hw_output_idx];
+	if (devc->channels) {
+		/* Dynamically-probed devices. */
+		ch_spec = &devc->channels[pch->hw_output_idx];
+	} else {
+		/* Statically-configured devices. */
+		ch_spec = &devc->device->channels[pch->hw_output_idx];
+	}
 	packet.type = SR_DF_ANALOG;
 	packet.payload = &analog;
 	/* Note: digits/spec_digits will be overridden later. */