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Summary:ASTERISK-14627: [patch] ARG Variables are not overwritten when using empty values on macros
Reporter:dillec (dillec)Labels:
Date Opened:2009-08-10 16:12:31Date Closed:2011-06-07 14:08:16
Priority:MinorRegression?No
Status:Closed/CompleteComponents:PBX/pbx_ael
Versions:Frequency of
Occurrence
Related
Issues:
Environment:Attachments:( 0) asterisk-1.6.1.2-ael_macro_null_args.diff
( 1) asterisk-1.6.2.0-rc8-ael_macro_null_args.diff.txt
Description:If you pass emtpy values inside of a macro to another macro, the ARG arguments are not overwritten:

&MacroOne("one","two","three","four");

macro MacroOne (var1, var2, var3, var4) {
  var3=""; // also tried var=${} here - makes no difference
  &MacroTwo(${var1},${var2},${var4},${var3});
};

macro MacroTwo (var1, var2, var3, var4) {
  Verbose("Arg1 ${ARG1} Arg2 ${ARG2} Arg3 ${ARG3} Arg4 ${ARG4}");
};

As you can see in the output below, four is also assigned to var4 in MacroTwo although it is passed as an empty value.


****** ADDITIONAL INFORMATION ******

   -- Executing [flow@2307_1:2] Gosub("SIP/micha-ee937418", "MacroOne,s,1("one","two","three","four")") in new stack
   -- Executing [s@MacroOne:1] MSet("SIP/micha-ee937418", "LOCAL(var1)=one") in new stack
   -- Executing [s@MacroOne:2] MSet("SIP/micha-ee937418", "LOCAL(var2)=two") in new stack
   -- Executing [s@MacroOne:3] MSet("SIP/micha-ee937418", "LOCAL(var3)=three") in new stack
   -- Executing [s@MacroOne:4] MSet("SIP/micha-ee937418", "LOCAL(var4)=four") in new stack
   -- Executing [s@MacroOne:5] MSet("SIP/micha-ee937418", "var3=""") in new stack
   -- Executing [s@MacroOne:6] Gosub("SIP/micha-ee937418", "MacroTwo,s,1(one,two,four,)") in new stack
   -- Executing [s@MacroTwo:1] MSet("SIP/micha-ee937418", "LOCAL(var1)=one") in new stack
   -- Executing [s@MacroTwo:2] MSet("SIP/micha-ee937418", "LOCAL(var2)=two") in new stack
   -- Executing [s@MacroTwo:3] MSet("SIP/micha-ee937418", "LOCAL(var3)=four") in new stack
   -- Executing [s@MacroTwo:4] MSet("SIP/micha-ee937418", "LOCAL(var4)=four") in new stack
   -- Executing [s@MacroTwo:5] Verbose("SIP/micha-ee937418", ""Arg1 one Arg2 two Arg3 four Arg4 four"") in new stack
Arg1 one Arg2 two Arg3 four Arg4 four
Comments:By: Tim Ferguson (crashhd) 2009-12-17 01:40:42.000-0600

Possible relation to 16458?
By: Corey Farrell (coreyfarrell) 2009-12-29 12:52:59.000-0600

CrashHD: I don't believe this ticket is related to 16458.
By: Corey Farrell (coreyfarrell) 2009-12-29 13:32:01.000-0600

I've experience this issue as well, I've worked around in AEL scripts by clearing ARG# variables.  AEL uses ARG# variables for temporary storage of macro/gosub parameters, but never clears the variables.  AEL generates the following contexts for MacroOne:

[ Context 'MacroOne' created by 'pbx_ael' ]
 's' =>            1. MSet(LOCAL(var1)=${ARG1})                  [pbx_ael]
                   2. MSet(LOCAL(var2)=${ARG2})                  [pbx_ael]
                   3. MSet(LOCAL(var3)=${ARG3})                  [pbx_ael]
                   4. MSet(LOCAL(var4)=${ARG4})                  [pbx_ael]
                   5. MSet(var3=$[""])                           [pbx_ael]
                   6. Gosub(MacroTwo,s,1(${var1},${var2},${var4},${var3})) [pbx_ael]
                   7. Return()                                   [pbx_ael]

The problem is that ARG4 is never cleared.  Gosub(MacroTwo,s,1(${var1},${var2},${var4},${var3})) seems to skip assignment of ARG4 since ${var3} is blank.  My patch causes the following context to be generated by the same AEL code:

[ Context 'MacroOne' created by 'pbx_ael' ]
 's' =>            1. MSet(LOCAL(var1)=${ARG1},ARG1=)            [pbx_ael]
                   2. MSet(LOCAL(var2)=${ARG2},ARG2=)            [pbx_ael]
                   3. MSet(LOCAL(var3)=${ARG3},ARG3=)            [pbx_ael]
                   4. MSet(LOCAL(var4)=${ARG4},ARG4=)            [pbx_ael]
                   5. MSet(var3=$[""])                           [pbx_ael]
                   6. Gosub(MacroTwo,s,1(${var1},${var2},${var4},${var3})) [pbx_ael]
                   7. Return()                                   [pbx_ael]

I'm not sure if this should corrected in the Gosub code (ensure that blank parameters are processed).  I choose to clear ARG# variables at the start of each procedure.  The patch attached for 1.6.2.0-rc8 is good for 1.6.2.0 release.

Without the patch this issue can be worked around by manually clearing ARG# variables at the start of procedures:

macro MacroOne (var1, var2, var3, var4) {
  ARG1="";
  ARG2="";
  ARG3="";
  ARG4=""; // this set's the default value of ARG4 to blank instead of retaining the value of ${var4}
  var3="";
  &MacroTwo(${var1},${var2},${var4},${var3});
  // can also use: &MacroTwo(${var1},${var2},${var4},);
};
By: Tilghman Lesher (tilghman) 2009-12-29 17:32:52.000-0600

Already fixed in 1.6.0.14 and 1.6.1.5.  Please, in the future, try the latest release before reporting an issue, because the problem you're reporting may already be fixed.