[sdf, usd] Fix crash when URL-encoded characters are used to generate session layer identifiers

[asluk]

[sdf, usd] Fix crash when URL-encoded characters are used to generate session layer identifiers

When opening a stage whose root layer has URL-encoded characters, sequences such as %20 for spaces could get misinterpreted as format strings when generating session layer identifiers on the fly via TfStringPrintf. This change uses stringstreams to ensure that URL-encoded characters never get misinterpreted on this codepath, which was previously leading to crashes such as the one in the testUsdStage case added here.

Thanks to Seema Kulkarni and Edward Slavin for earlier work on this PR.

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[asluk]

Looks like there are some newly failing tests after I rebased to latest dev; will try to look into those over the next couple weeks.

[tallytalwar]

Filed as internal issue #USD-7612

[meshula]

Looks good, thanks!

[meshula]

Hi @asluk ! I haven't debugged yet to see what's going wrong, but I wanted to give you a heads up that I haven't had a successful test run ~

====================================================================== 
ERROR: test_URLEncodedIdentifiers (__main__.TestUsdStage)
 ---------------------------------------------------------------------- 
Traceback (most recent call last): 

File "/scratch/build_local/dev/src/inst/fedora-gcc64-opt/pxr/tests/testUsdStage", 
line 33, in test_URLEncodedIdentifiers
  stage = Usd.Stage.Open("Libeccio%20LowFBX.usda") 
pixar.Tf.ErrorException:  Error in 'UsdStage::Open' at line 879 in file pxr/usd/usd/stage.cpp : 
   'Failed to open layer @Libeccio%20LowFBX.usda@'

[asluk]

Hi @asluk ! I haven't debugged yet to see what's going wrong, but I wanted to give you a heads up that I haven't had a successful test run ~

====================================================================== 
ERROR: test_URLEncodedIdentifiers (__main__.TestUsdStage)
 ---------------------------------------------------------------------- 
Traceback (most recent call last): 

File "/scratch/build_local/dev/src/inst/fedora-gcc64-opt/pxr/tests/testUsdStage", 
line 33, in test_URLEncodedIdentifiers
  stage = Usd.Stage.Open("Libeccio%20LowFBX.usda") 
pixar.Tf.ErrorException:  Error in 'UsdStage::Open' at line 879 in file pxr/usd/usd/stage.cpp : 
   'Failed to open layer @Libeccio%20LowFBX.usda@'

Thanks @meshula ... it's passing for me on Windows; will try it on Ubuntu via WSL2 next week (are the Azure pipelines running tests? They are all passing, but I forget if they are only compiling). 🙏

[tallytalwar]

@asluk yeah azure pipeline doesn't run tests at present. We want to get to it but I think timeouts are a concern there! https://github.com/PixarAnimationStudios/USD/blob/release/azure-pipelines.yml

[asluk]

Hi @asluk ! I haven't debugged yet to see what's going wrong, but I wanted to give you a heads up that I haven't had a successful test run ~

====================================================================== 
ERROR: test_URLEncodedIdentifiers (__main__.TestUsdStage)
 ---------------------------------------------------------------------- 
Traceback (most recent call last): 

File "/scratch/build_local/dev/src/inst/fedora-gcc64-opt/pxr/tests/testUsdStage", 
line 33, in test_URLEncodedIdentifiers
  stage = Usd.Stage.Open("Libeccio%20LowFBX.usda") 
pixar.Tf.ErrorException:  Error in 'UsdStage::Open' at line 879 in file pxr/usd/usd/stage.cpp : 
   'Failed to open layer @Libeccio%20LowFBX.usda@'

Thanks @meshula ... it's passing for me on Windows; will try it on Ubuntu via WSL2 next week (are the Azure pipelines running tests? They are all passing, but I forget if they are only compiling). 🙏

Thanks @meshula and @tallytalwar -- the test is passing for me on Windows and on Ubuntu via WSL2; not sure what might be happening differently on Fedora :(