From: Soeren Apel <redacted>
Date: Tue, 3 May 2016 06:53:24 +0000 (+0200)
Subject: Fix #792 by making sure we don't request samples that don't exist
X-Git-Tag: pulseview-0.4.0~298
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=40ec0302a21055e85572ced539c457f0d8484c82;p=pulseview.git

Fix #792 by making sure we don't request samples that don't exist
---

diff --git a/pv/mainwindow.cpp b/pv/mainwindow.cpp
index 1a05907c..4f6bc41d 100644
--- a/pv/mainwindow.cpp
+++ b/pv/mainwindow.cpp
@@ -74,6 +74,7 @@ using std::cerr;
 using std::endl;
 using std::list;
 using std::map;
+using std::max;
 using std::pair;
 using std::shared_ptr;
 using std::string;
@@ -257,7 +258,8 @@ void MainWindow::export_file(shared_ptr<OutputFormat> format,
 		const pv::util::Timestamp& start_time = view_->cursors()->first()->time();
 		const pv::util::Timestamp& end_time = view_->cursors()->second()->time();
 
-		const uint64_t start_sample = start_time.convert_to<double>() * samplerate;
+		const uint64_t start_sample =
+			std::max((double)0, start_time.convert_to<double>() * samplerate);
 		const uint64_t end_sample = end_time.convert_to<double>() * samplerate;
 
 		sample_range = std::make_pair(start_sample, end_sample);
diff --git a/pv/storesession.cpp b/pv/storesession.cpp
index 9a481dd8..2a4c8500 100644
--- a/pv/storesession.cpp
+++ b/pv/storesession.cpp
@@ -160,16 +160,20 @@ bool StoreSession::start()
 	}
 
 	// Check whether the user wants to export a certain sample range
+	uint64_t end_sample;
+
 	if (sample_range_.first == sample_range_.second) {
 		start_sample_ = 0;
 		sample_count_ =	any_segment->get_sample_count();
 	} else {
 		if (sample_range_.first > sample_range_.second) {
 			start_sample_ = sample_range_.second;
-			sample_count_ = sample_range_.first - sample_range_.second;
+			end_sample = min(sample_range_.first, any_segment->get_sample_count());
+			sample_count_ = end_sample - start_sample_;
 		} else {
 			start_sample_ = sample_range_.first;
-			sample_count_ = sample_range_.second - sample_range_.first;
+			end_sample = min(sample_range_.second, any_segment->get_sample_count());
+			sample_count_ = end_sample - start_sample_;
 		}
 	}