Index: openacs-4/packages/acs-tcl/tcl/exception-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/exception-procs.tcl,v
diff -u -N -r1.6 -r1.7
--- openacs-4/packages/acs-tcl/tcl/exception-procs.tcl	6 Dec 2017 10:09:20 -0000	1.6
+++ openacs-4/packages/acs-tcl/tcl/exception-procs.tcl	10 Dec 2017 15:15:45 -0000	1.7
@@ -42,44 +42,115 @@
     return ""
 }
 
-ad_proc -private ad_try {code args} {
+if {$::tcl_version eq "8.6"} {
 
-    @author rhs@mit.edu
-    @creation-date 2000-09-09
+    #
+    # Tcl 8.6 variant of ad_try
+    #
+    
+    ad_proc ad_try {
+        {-auto_abort:boolean true}
+        body
+        args
+    } {
+        
+        Generic code for OpenACS to handle exceptions and traps based on
+        Tcl's primitives. This implementation is a slight generalization
+        of the Tcl 8.6 builtin ::try, which handles ad_script_aborts
+        automatically.
 
-    Executes $code, catches any exceptions thrown by ad_raise and runs
-    any matching exception handlers.
+        The command "ad_try" should replace the various exception handling
+        constructs such as "catch", which tend to swallow often error
+        conditions, making debugging unnecessarily hard.  It will make
+        "with_finally" and "with_catch" obsolete, which should be marked
+        as deprecated in the not-to-far future.
 
-    If you use this I will kill you.
+        @see with_finally 
+        @see with_catch
+        
+    } {
+        #
+        # Per default, ad_script_abort exceptions are automatically passed
+        # through the higher handlers, aborting all execution levels. Only
+        # the top-level processor should handle these cases (probably
+        # silently).
+        #
+        set extraTraps {}
+        if {$auto_abort_p} {
+            #
+            # The "subst" below is just used for resolving $body in
+            # the debug message.
+            #
+            lappend extraTraps \
+                trap {AD EXCEPTION ad_script_abort} {result} [subst {
+                    puts stderr "ad_script_abort of <$body> return value <\$result>"
+                    ::throw {AD EXCEPTION ad_script_abort} \$result
+                }]
+        }
+        #
+        # Call the Tcl 8.6 builtin/compliant ::try in the scope of the caller
+        #
+        #puts stderr EXEC=[list ::try $body {*}$extraTraps {*}$args]
+        
+        tailcall ::try $body {*}$extraTraps {*}$args
+    }
+    
+} else {
+    # version for Tcl 8.5
 
-    @see with_finally 
-    @see with_catch
-} {
+    ad_proc ad_try {
+        {-auto_abort:boolean true}
+        body
+        args
+    } {
+        
+        Generic code for OpenACS to handle exceptions and traps based on
+        Tcl's primitives. This implementation is a slight generalization
+        of the Tcl 8.6 builtin ::try, which handles ad_script_aborts
+        automatically.
 
-    if {[set errno [catch {uplevel $code} result]]} {
-        if {$errno == 1 
-            && [lindex $::errorCode 0] eq "AD"
-            && [lindex $::errorCode 1] eq "EXCEPTION"
-        } {
-            set exception [lindex $::errorCode 2]
+        The command "ad_try" should replace the various exception handling
+        constructs such as "catch", which tend to swallow often error
+        conditions, making debugging unnecessarily hard.  It will make
+        "with_finally" and "with_catch" obsolete, which should be marked
+        as deprecated in the not-to-far future.
 
-            set matched 0
-            for {set i 0} {$i < [llength $args]} {incr i 3} {
-                if {[string match [lindex $args $i] $exception]} {
-                    set matched 1
-                    break
-                }
-            }
-
-            if {$matched} {
-                upvar [lindex $args $i+1] var
-                set var $result
-                set errno [catch {uplevel [lindex $args $i+2]} result]
-            }
+        @see with_finally 
+        @see with_catch
+        
+    } {
+        #
+        # Per default, ad_script_abort exceptions are automatically passed
+        # through the higher handlers, aborting all execution levels. Only
+        # the top-level processor should handle these cases (probably
+        # silently).
+        #
+        set extraTraps {}
+        if {$auto_abort_p} {
+            #
+            # The "subst" below is just used for resolving $body in
+            # the debug message.
+            #
+            lappend extraTraps \
+                trap {AD EXCEPTION ad_script_abort} {result} [subst {
+                    puts stderr "ad_script_abort of <$body> return value <\$result>"
+                    ::throw {AD EXCEPTION ad_script_abort} \$result
+                }]
         }
+        #
+        # Call the Tcl 8.6 builtin/compliant ::try in the scope of the caller
+        #
+        #puts stderr EXEC=[list ::try $body {*}$extraTraps {*}$args]
+        
+        #uplevel [list ::try $body {*}$extraTraps {*}$args]
 
-        return -code $errno -errorcode $::errorCode -errorinfo $::errorInfo $result
-    }
+        if {[catch {uplevel [list ::try $body {*}$extraTraps {*}$args]} msg opts]} {
+            dict incr opts -level
+            return {*}$opts $msg
+        } else {
+            return $msg
+        }
+    }    
 }
 
 # Local variables: