As shown in bug 1408975 comment 8, we have a problem with the addon scalar API: if we register scalar A and then try to register again scalars A and B together, scalar B won't get registered because scalar A was already registered. We should fix that by changing [1] to skip existing scalars but register new ones. [1] - http://searchfox.org/mozilla-central/rev/a984558fa2bbde6492d3fb918496fc0b0835b2ce/toolkit/components/telemetry/TelemetryScalar.cpp#1395

We should fix this for 58, which still has about a month left on Nightly.

Comment on attachment 8925866 [details] Bug 1409323 - Allow to register new addon scalars for an existing category. https://reviewboard.mozilla.org/r/197066/#review202256 One nit ::: toolkit/components/telemetry/TelemetryScalar.cpp:2749 (Diff revision 1) > } > > /** > * This adds the dynamic scalar definitions coming from > - * the parent process to this child process. > + * the parent process to this child process. If a dynamic > + * scalar definition is already, check if the new definition "If a dynamic scalar definition is already" think you want the word "defined" in there after "already"

Pushed by alessio.placitelli@gmail.com: https://hg.mozilla.org/integration/autoland/rev/93469c0e79b6 Allow to register new addon scalars for an existing category. r=chutten