[gnuastro-commits] master 858667d: NoiseChisel checks if there was any detection

[Mohammad Akhlaghi]

branch: master
commit 858667d3021e3e5411ceb3c4cf7b11d045e0592d
Author: Mohammad Akhlaghi <address@hidden>
Commit: Mohammad Akhlaghi <address@hidden>

    NoiseChisel checks if there was any detection
    
    Until now, NoiseChisel assumed that there is always a detection. It would
    thus crash if there wasn't any. So a check was added after the detection
    step so NoiseChisel continues only when there are any detections.
    
    This issue came up in a dataset provided by Sara Yousefi Taemeh.
    
    This fixes bug #53304.
---
 NEWS                          |  2 ++
 bin/noisechisel/noisechisel.c | 42 ++++++++++++++++++++++++++++--------------
 2 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/NEWS b/NEWS
index 0fd4fd6..0c88d37 100644
--- a/NEWS
+++ b/NEWS
@@ -48,6 +48,8 @@ GNU Astronomy Utilities NEWS                          -*- 
outline -*-
 
   MakeCatalog parses area larger than clump (bug #53295).
 
+  NoiseChisel crash when there is no detection (bug #53304).
+
 
 
 * Noteworthy changes in release 0.5 (library 3.0.0) (2017-12-22) [stable]
diff --git a/bin/noisechisel/noisechisel.c b/bin/noisechisel/noisechisel.c
index a9e4f60..4e5656f 100644
--- a/bin/noisechisel/noisechisel.c
+++ b/bin/noisechisel/noisechisel.c
@@ -23,6 +23,8 @@ along with Gnuastro. If not, see 
<http://www.gnu.org/licenses/>.
 #include <config.h>
 
 #include <stdio.h>
+#include <errno.h>
+#include <error.h>
 #include <stdlib.h>
 
 #include <gnuastro/fits.h>
@@ -325,22 +327,34 @@ noisechisel(struct noisechiselparams *p)
   /* Remove false detections. */
   detection(p);
 
-  /* Find the Sky value and subtract it from the input and convolved
-     images. */
-  noisechisel_find_sky_subtract(p);
-
-  /* If the user only wanted detection, ignore the segmentation steps. */
-  if(p->onlydetection==0)
+  /* If we have any detections, find the Sky value and subtract it from the
+     input and convolved images. */
+  if(p->numdetections)
     {
-      /* Correct the convolved image channel edges if necessary. */
-      noisechisel_convolve_correct_ch_edges(p);
+      noisechisel_find_sky_subtract(p);
+
+      /* If the user only wanted detection, ignore the segmentation steps. */
+      if(p->onlydetection==0)
+        {
+          /* Correct the convolved image channel edges if necessary. */
+          noisechisel_convolve_correct_ch_edges(p);
 
-      /* Do the segmentation. */
-      segmentation(p);
+          /* Do the segmentation. */
+          segmentation(p);
+        }
+      else
+        p->numobjects=p->numdetections;
+
+      /* Write the output. */
+      noisechisel_output(p);
     }
   else
-    p->numobjects=p->numdetections;
-
-  /* Write the output. */
-  noisechisel_output(p);
+    {
+      if(p->cp.quiet)
+        error(0, 0, "no output file created: no detections could found "
+              "in `%s' with given parameters", p->inputname);
+      else
+        gal_timing_report(NULL, "NO OUTPUT FILE CREATED (try with "
+                          "`--checkdetection' to see why)", 1);
+    }
 }