0023489: Memory leak in TNaming_NamedShape

Added test for memory leak (bugs/ocaf/bug23489)
Missing return added in QANewBRepNaming_BooleanOperationFeat::IsWRCase2()
Adding test case and general procedure for trend checking for detection of memory leaks

src/QANewBRepNaming/QANewBRepNaming_BooleanOperationFeat.cxx

@@ -1565,6 +1565,7 @@ Standard_Boolean QANewBRepNaming_BooleanOperationFeat::IsWRCase2(const BRepAlgoA
       }
     }
   }
+  return Standard_False;
 }
 
 //=======================================================================

src/TNaming/TNaming_NamedShape.cdl

@@ -80,6 +80,7 @@ is
 	---C++: inline         
 
     Clear (me : mutable);
+    ---C++: alias ~
 
     ID(me) returns GUID from Standard
     	is redefined static;

tests/bugs/begin

@@ -25,6 +25,55 @@ if { [info exists test_image] == 0 } {
    set test_image photo
 }
 
+# Procedure to check if sequence of values in listval follows linear trend
+# adding the same delta on each step.
+#
+# The function does statistical estimation of the mean variation of the
+# values of the sequence, and dispersion, and returns true only if both 
+# dispersion and deviation of the mean from expected delta are within 
+# specified tolerance.
+#
+# If mean variation differs from expected delta on more than two dispersions,
+# the check fails and procedure raises error with specified message.
+#
+# Otherwise the procedure returns false meaning that more iterations are needed.
+# Note that false is returned in any case if length of listval is less than 3.
+#
+# See example of use to check memory leaks in bugs/caf/bug23489
+#
+proc checktrend {listval delta tolerance message} {
+    set nbval [llength $listval]
+    if { $nbval < 3} {
+        return 0
+    }
 
+    # calculate mean value
+    set mean 0.
+    set prev [lindex $listval 0]
+    foreach val [lrange $listval 1 end] {
+        set mean [expr $mean + ($val - $prev)]
+        set prev $val
+    }
+    set mean [expr $mean / $nbval]
 
+    # calculate dispersion
+    set sigma 0.
+    set prev [lindex $listval 0]
+    foreach val [lrange $listval 1 end] {
+        set d [expr ($val - $prev) - $mean]
+        set sigma [expr $sigma + $d * $d]
+        set prev $val
+    }
+    set sigma [expr sqrt ($sigma / ($nbval - 1))]
 
+    puts "Checking trend: nb = $nbval, mean delta = $mean, sigma = $sigma"
+
+    # check if deviation is definitely too big
+    if { abs ($mean - $delta) > 2. * $sigma } {
+        puts "Checking trend failed: mean delta per step = $mean, sigma = $sigma, expected delta = $delta"
+        error $message
+    }
+
+    # check if deviation is clearly within a range
+    return [expr abs ($mean - $delta) <= $sigma && $sigma <= $tolerance]
+}

tests/bugs/caf/bug23489

@@ -0,0 +1,32 @@
+# Test for #23489: memory leak in TNaming_NamedShape destructor
+
+pload OCAF
+
+set listmem {}
+for {set i 1} {$i < 10} {incr i} {
+    # load big shape
+    restore [locate_data_file bug23489_Bottom.brep] a
+
+    # add shape to new OCAF document
+    NewDocument D MDTV-Standard
+
+    # add shape to document
+    SetShape D 0:1 a
+
+    # Note: if ForgetAll or Undo is called here, memory is correctly freed!
+    # ForgetAll D 0:1
+
+    # close document
+    Close D
+    unset D
+
+    # unload shape (replace by small one)
+    vertex a 0 0 0
+
+    # check memory usage (with tolerance equal to half page size)
+    lappend listmem [expr [meminfo w] / 1024]
+    if { [checktrend $listmem 0 256 "Memory leak detected"] } {
+        puts "No memory leak, $i iterations"
+        break
+    }
+}

tests/bugs/grids.list

@@ -6,4 +6,6 @@
 006 modalg
 007 moddata
 008 step
+009 caf
+