fixed ApplyToSection to correctly deal with empty matrix operator

mohamed-barakat · Feb 28, 2015 · ee230ea · ee230ea
1 parent e5050c9
commit ee230ea
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Showing 2 changed files with 9 additions and 3 deletions.
diff --git a/PackageInfo.g b/PackageInfo.g
@@ -27,7 +27,7 @@ Subtitle := "A homalg based package for D-modules",
 ##  See '?Extending: Version Numbers' in GAP help for an explanation
 ##  of valid version numbers. For an automatic package distribution update
 ##  you must provide a new version number even after small changes.
-Version := "2014.07.05",
+Version := "2015.02.11",
 ##  Please adjust also the VERSION file in the package directory when
 ##  changing this.
 

diff --git a/gap/Tools.gi b/gap/Tools.gi
@@ -57,10 +57,16 @@ InstallMethod( ApplyToSection,
         [ IsHomalgMatrix, IsHomalgMatrix ],
 
   function( mat, u )
-    local R, RP, sec;
+    local R, r, RP, sec;
 
     R := HomalgRing( mat );
 
+    r := NrRows( mat );
+
+    if r = 0 then
+        return HomalgZeroMatrix( r, 1, R );
+    fi;
+
     RP := homalgTable( R );
 
     if not IsBound( RP!.ApplyToSection ) then
@@ -69,7 +75,7 @@ InstallMethod( ApplyToSection,
 
     sec := RP!.ApplyToSection( mat, u );	## the external object
 
-    return HomalgMatrix( sec, NrRows( mat ), 1, R );
+    return HomalgMatrix( sec, r, 1, R );
 
 end );