I dragged an add-on onto the browser to install it. Not sure if important: the add-on was already installed in the same version but nevertheless I got the install dialog and proceeded. This is what about:cc shows: 0x118f4b000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/general.xml Roots: 5 0x118fc9c90 [rc=410] root nsXBLDocumentInfo 0x11922e480 [rc=3] root nsGenericElement (XBL) children chrome://global/content/bindings/general.xml 0x119234a40 [rc=2] root nsXULPrototypeNode 0x119234fc0 [rc=9] root nsXULPrototypeNode 0x119234a80 [rc=2] root nsXULPrototypeNode 0x116c2b800 [rc=2] nsDocument normal ([none]) chrome://global/content/platformHTMLBindings.xml Roots: 1 0x11977c790 [rc=8] root nsXBLDocumentInfo 0x11927f800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/toolbar.xml Roots: 1 0x119289e20 [rc=38] root nsXBLDocumentInfo 0x11927f000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/stringbundle.xml Roots: 1 0x119289d30 [rc=18] root nsXBLDocumentInfo 0x119a09800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/notification.xml Roots: 13 0x119abcec0 [rc=8] root nsXBLDocumentInfo 0x119ac15c0 [rc=2] root nsXULPrototypeNode 0x119ac1ec0 [rc=2] root nsXULPrototypeNode 0x119ac1f80 [rc=2] root nsXULPrototypeNode 0x119ac1680 [rc=2] root nsXULPrototypeNode 0x119ac1e80 [rc=2] root nsXULPrototypeNode 0x119ac1d00 [rc=2] root nsXULPrototypeNode 0x119ac1f00 [rc=2] root nsXULPrototypeNode 0x119af4100 [rc=2] root nsXULPrototypeNode 0x119ac1dc0 [rc=2] root nsXULPrototypeNode 0x119af41c0 [rc=2] root nsXULPrototypeNode 0x119ac1d80 [rc=2] root nsXULPrototypeNode 0x119af4180 [rc=2] root nsXULPrototypeNode 0x121eb6800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/richlistbox.xml Roots: 2 0x118f03b50 [rc=18] root nsXBLDocumentInfo 0x123a22300 [rc=2] root nsXULPrototypeNode 0x119807000 [rc=2] nsDocument normal ([none]) chrome://browser/content/tabbrowser.xml Roots: 25 0x1197cee20 [rc=23] root nsXBLDocumentInfo 0x119770800 [rc=2] root nsXULPrototypeNode 0x1197ddba0 [rc=13] root nsNodeInfo (XBL) inherits 0x1198efc40 [rc=3] root nsXULPrototypeNode 0x1190978b0 [rc=6] root nsGenericElement (XUL) hbox class='tab-content' chrome://browser/content/browser.xul 0x1198efbc0 [rc=3] root nsXULPrototypeNode 0x1198efc80 [rc=3] root nsXULPrototypeNode 0x1198efb80 [rc=3] root nsXULPrototypeNode 0x1198ef900 [rc=3] root nsXULPrototypeNode 0x1198ef9c0 [rc=3] root nsXULPrototypeNode 0x1198efa80 [rc=3] root nsXULPrototypeNode 0x1198efb00 [rc=3] root nsXULPrototypeNode 0x119a251c0 [rc=2] root nsXULPrototypeNode 0x1198efcc0 [rc=3] root nsXULPrototypeNode 0x1198ef1c0 [rc=2] root nsXULPrototypeNode 0x119a25140 [rc=2] root nsXULPrototypeNode 0x1198ef140 [rc=2] root nsXULPrototypeNode 0x1198ef280 [rc=2] root nsXULPrototypeNode 0x1198ef880 [rc=3] root nsXULPrototypeNode 0x1197709c0 [rc=2] root nsXULPrototypeNode 0x1198ef340 [rc=2] root nsXULPrototypeNode 0x1198ef380 [rc=2] root nsXULPrototypeNode 0x119770780 [rc=2] root nsXULPrototypeNode 0x119770880 [rc=2] root nsXULPrototypeNode 0x119770940 [rc=2] root nsXULPrototypeNode 0x119a03000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/tabbox.xml Roots: 1 0x1198f4830 [rc=15] root nsXBLDocumentInfo 0x119adb000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/browser.xml Roots: 1 0x119af35b0 [rc=4] root nsXBLDocumentInfo 0x119742000 [rc=2] nsDocument normal ([none]) chrome://browser/content/search/search.xml Roots: 12 0x11977cc90 [rc=7] root nsXBLDocumentInfo 0x1197fdcc0 [rc=2] root nsXULPrototypeNode 0x1197fdd80 [rc=2] root nsXULPrototypeNode 0x1197fddc0 [rc=2] root nsXULPrototypeNode 0x1197e9280 [rc=2] root nsXULPrototypeNode 0x1197fdf40 [rc=2] root nsXULPrototypeNode 0x1197fde40 [rc=2] root nsXULPrototypeNode 0x1197e92c0 [rc=2] root nsXULPrototypeNode 0x1197e9080 [rc=2] root nsXULPrototypeNode 0x1197e9100 [rc=2] root nsXULPrototypeNode 0x1197e9180 [rc=2] root nsXULPrototypeNode 0x1197e9200 [rc=2] root nsXULPrototypeNode 0x118f4b800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/popup.xml Roots: 10 0x1192577e0 [rc=194] root nsXBLDocumentInfo 0x119266e80 [rc=10] root nsGenericElement (XBL) children chrome://global/content/bindings/popup.xml 0x11924d800 [rc=5] root nsXULPrototypeNode 0x11924d5c0 [rc=5] root nsXULPrototypeNode 0x11924d780 [rc=5] root nsXULPrototypeNode 0x11924d940 [rc=5] root nsXULPrototypeNode 0x11924d540 [rc=5] root nsXULPrototypeNode 0x11924d280 [rc=67] root nsXULPrototypeNode 0x11924db00 [rc=5] root nsXULPrototypeNode 0x11924d6c0 [rc=5] root nsXULPrototypeNode 0x1192dc800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/button.xml Roots: 9 0x118cfcc90 [rc=37] root nsXBLDocumentInfo 0x1187d2e00 [rc=4] root nsGenericElement (XBL) children chrome://global/content/bindings/button.xml 0x1187d2b80 [rc=4] root nsGenericElement (XBL) children chrome://global/content/bindings/button.xml 0x11971dac0 [rc=2] root nsXULPrototypeNode 0x11971d4c0 [rc=2] root nsXULPrototypeNode 0x11971d1c0 [rc=2] root nsXULPrototypeNode 0x11971db80 [rc=2] root nsXULPrototypeNode 0x11971d2c0 [rc=2] root nsXULPrototypeNode 0x11971d380 [rc=2] root nsXULPrototypeNode 0x1192dd000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/text.xml Roots: 1 0x119720650 [rc=160] root nsXBLDocumentInfo 0x119a09000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/splitter.xml Roots: 1 0x1198bf5b0 [rc=4] root nsXBLDocumentInfo 0x119a9f000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/scrollbar.xml Roots: 7 0x119ca34c0 [rc=31] root nsXBLDocumentInfo 0x119ca5380 [rc=10] root nsXULPrototypeNode 0x119ca5340 [rc=10] root nsXULPrototypeNode 0x119883cc0 [rc=10] root nsXULPrototypeNode 0x119ca5480 [rc=10] root nsXULPrototypeNode 0x119ca54c0 [rc=10] root nsXULPrototypeNode 0x119ca5400 [rc=10] root nsXULPrototypeNode 0x1192de000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/textbox.xml Roots: 10 0x119720ba0 [rc=12] root nsXBLDocumentInfo 0x119769500 [rc=3] root nsXULPrototypeNode 0x119769580 [rc=3] root nsXULPrototypeNode 0x119769640 [rc=3] root nsXULPrototypeNode 0x119769680 [rc=3] root nsXULPrototypeNode 0x1197696c0 [rc=3] root nsXULPrototypeNode 0x119769700 [rc=3] root nsXULPrototypeNode 0x1197695c0 [rc=3] root nsXULPrototypeNode 0x119769600 [rc=3] root nsXULPrototypeNode 0x119769740 [rc=3] root nsXULPrototypeNode 0x119803000 [rc=2] nsDocument normal ([none]) chrome://browser/content/places/menu.xml Roots: 5 0x1197fb240 [rc=6] root nsXBLDocumentInfo 0x1197e5900 [rc=4] root nsXULPrototypeNode 0x1197e5700 [rc=4] root nsXULPrototypeNode 0x1197e5740 [rc=4] root nsXULPrototypeNode 0x1197e5800 [rc=4] root nsXULPrototypeNode 0x1192db800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/toolbarbutton.xml Roots: 7 0x1187c4970 [rc=34] root nsXBLDocumentInfo 0x1187d1400 [rc=7] root nsXULPrototypeNode 0x1187d1140 [rc=18] root nsXULPrototypeNode 0x1187d1340 [rc=7] root nsXULPrototypeNode 0x1187d18c0 [rc=2] root nsXULPrototypeNode 0x1187d1200 [rc=18] root nsXULPrototypeNode 0x1187d13c0 [rc=7] root nsXULPrototypeNode 0x119a3b000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/listbox.xml Roots: 1 0x116ab64c0 [rc=23] root nsXBLDocumentInfo 0x118c52800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/autocomplete.xml Roots: 30 0x118c39600 [rc=36] root nsXBLDocumentInfo 0x118c4df80 [rc=3] root nsGenericElement (XBL) children chrome://global/content/bindings/autocomplete.xml 0x118c5af00 [rc=2] root nsXULPrototypeNode 0x118ef6280 [rc=2] root nsXULPrototypeNode 0x1192fdc40 [rc=2] root nsXULPrototypeNode 0x1192fdd80 [rc=13] root nsXULPrototypeNode 0x118ce43c0 [rc=13] root nsXULPrototypeNode 0x1192fdf40 [rc=13] root nsXULPrototypeNode 0x118ce4180 [rc=13] root nsXULPrototypeNode 0x118ce4500 [rc=13] root nsXULPrototypeNode 0x1192fd080 [rc=2] root nsXULPrototypeNode 0x1192fd0c0 [rc=2] root nsXULPrototypeNode 0x1192fde80 [rc=13] root nsXULPrototypeNode 0x118ce4100 [rc=13] root nsXULPrototypeNode 0x118ce46c0 [rc=13] root nsXULPrototypeNode 0x118ce4040 [rc=13] root nsXULPrototypeNode 0x118ce4240 [rc=13] root nsXULPrototypeNode 0x118ce42c0 [rc=13] root nsXULPrototypeNode 0x118ce45c0 [rc=13] root nsXULPrototypeNode 0x118ce4680 [rc=13] root nsXULPrototypeNode 0x118ce4340 [rc=13] root nsXULPrototypeNode 0x118ce44c0 [rc=13] root nsXULPrototypeNode 0x118ce41c0 [rc=13] root nsXULPrototypeNode 0x1192fdc00 [rc=2] root nsXULPrototypeNode 0x1192fd640 [rc=2] root nsXULPrototypeNode 0x118ce4440 [rc=13] root nsXULPrototypeNode 0x118ce4740 [rc=13] root nsXULPrototypeNode 0x1192fd6c0 [rc=2] root nsXULPrototypeNode 0x1192fd880 [rc=2] root nsXULPrototypeNode 0x1192fd740 [rc=2] root nsXULPrototypeNode 0x1192d9800 [rc=2] nsDocument normal ([none]) chrome://browser/content/urlbarBindings.xml Roots: 12 0x118f1c6f0 [rc=18] root nsXBLDocumentInfo 0x1192e6680 [rc=3] root nsGenericElement (XBL) children chrome://browser/content/urlbarBindings.xml 0x118ef6440 [rc=2] root nsXULPrototypeNode 0x118ef65c0 [rc=2] root nsXULPrototypeNode 0x118c49d80 [rc=2] root nsXULPrototypeNode 0x118c49e00 [rc=2] root nsXULPrototypeNode 0x118ef6700 [rc=2] root nsXULPrototypeNode 0x118ef6740 [rc=2] root nsXULPrototypeNode 0x118c49ec0 [rc=2] root nsXULPrototypeNode 0x118c5a080 [rc=2] root nsXULPrototypeNode 0x118c49f40 [rc=2] root nsXULPrototypeNode 0x118c49fc0 [rc=2] root nsXULPrototypeNode 0x119806000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/scrollbox.xml Roots: 5 0x1197fb600 [rc=14] root nsXBLDocumentInfo 0x1198279c0 [rc=4] root nsXULPrototypeNode 0x119853080 [rc=2] root nsXULPrototypeNode 0x119827f40 [rc=2] root nsXULPrototypeNode 0x119853140 [rc=2] root nsXULPrototypeNode 0x119afb000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/menu.xml Roots: 22 0x1197b6f60 [rc=207] root nsXBLDocumentInfo 0x119ba4f80 [rc=3] root nsXULPrototypeNode 0x119ba4700 [rc=2] root nsXULPrototypeNode 0x119ba40c0 [rc=17] root nsXULPrototypeNode 0x119b96e00 [rc=35] root nsXULPrototypeNode 0x119ba4300 [rc=17] root nsXULPrototypeNode 0x119bad0c0 [rc=3] root nsXULPrototypeNode 0x119ba4800 [rc=2] root nsXULPrototypeNode 0x119ba4200 [rc=17] root nsXULPrototypeNode 0x119b96f00 [rc=35] root nsXULPrototypeNode 0x119ba4e40 [rc=3] root nsXULPrototypeNode 0x119bad040 [rc=3] root nsXULPrototypeNode 0x119bad180 [rc=3] root nsXULPrototypeNode 0x119ba4580 [rc=2] root nsXULPrototypeNode 0x119ba4780 [rc=2] root nsXULPrototypeNode 0x119ba4180 [rc=17] root nsXULPrototypeNode 0x119b96e80 [rc=35] root nsXULPrototypeNode 0x119b96fc0 [rc=35] root nsXULPrototypeNode 0x119ba4ec0 [rc=3] root nsXULPrototypeNode 0x119bad200 [rc=3] root nsXULPrototypeNode 0x119ba4600 [rc=2] root nsXULPrototypeNode 0x119bbc640 [rc=35] root nsXULPrototypeNode

Installing an add-on via AMO leaks a lot less: 0x1237c6000 [rc=3] nsDocument normal (xhtml) https://addons.mozilla.org/de/firefox/addon/facebook-auto-logout/ Roots: 1 0x1478efe10 [rc=2] root nsXPCWrappedJS (nsISupports)

Sorry for all the spam but I really hope this debug information is useful to someone. Another add-on I tried doesn't leak at all when installing but leaks when clicking "Remove" in about:addons. 0x11745d800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/toolbar.xml Roots: 1 0x117459a60 [rc=38] root nsXBLDocumentInfo 0x119a4d800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/scrollbar.xml Roots: 7 0x119e2b060 [rc=38] root nsXBLDocumentInfo 0x119e2ec00 [rc=12] root nsXULPrototypeNode 0x119e2ec80 [rc=12] root nsXULPrototypeNode 0x119e2ebc0 [rc=12] root nsXULPrototypeNode 0x119e2e640 [rc=12] root nsXULPrototypeNode 0x119e2ed80 [rc=12] root nsXULPrototypeNode 0x119e2edc0 [rc=12] root nsXULPrototypeNode 0x118966000 [rc=2] nsDocument normal ([none]) chrome://global/content/platformHTMLBindings.xml Roots: 1 0x117630330 [rc=8] root nsXBLDocumentInfo 0x118f66800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/toolbarbutton.xml Roots: 7 0x118f06510 [rc=35] root nsXBLDocumentInfo 0x118f42cc0 [rc=7] root nsXULPrototypeNode 0x118f42a00 [rc=17] root nsXULPrototypeNode 0x118f42c00 [rc=7] root nsXULPrototypeNode 0x118f581c0 [rc=3] root nsXULPrototypeNode 0x118f42ac0 [rc=17] root nsXULPrototypeNode 0x118f42c80 [rc=7] root nsXULPrototypeNode 0x119bae800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/browser.xml Roots: 1 0x119ba7150 [rc=5] root nsXBLDocumentInfo 0x1195b7000 [rc=2] nsDocument normal ([none]) chrome://browser/content/urlbarBindings.xml Roots: 6 0x117474290 [rc=16] root nsXBLDocumentInfo 0x1195af700 [rc=3] root nsGenericElement (XBL) children chrome://browser/content/urlbarBindings.xml 0x119136d40 [rc=2] root nsXULPrototypeNode 0x119136ec0 [rc=2] root nsXULPrototypeNode 0x1195fd040 [rc=2] root nsXULPrototypeNode 0x1195fd080 [rc=2] root nsXULPrototypeNode 0x119acf000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/notification.xml Roots: 3 0x119b75a60 [rc=7] root nsXBLDocumentInfo 0x119b67ec0 [rc=3] root nsXULPrototypeNode 0x119b67f80 [rc=3] root nsXULPrototypeNode 0x1193fe000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/popup.xml Roots: 10 0x118aaf380 [rc=194] root nsXBLDocumentInfo 0x118ac8f80 [rc=10] root nsGenericElement (XBL) children chrome://global/content/bindings/popup.xml 0x1174640c0 [rc=5] root nsXULPrototypeNode 0x118ab0e80 [rc=5] root nsXULPrototypeNode 0x117464040 [rc=5] root nsXULPrototypeNode 0x117464200 [rc=5] root nsXULPrototypeNode 0x118ab0e00 [rc=5] root nsXULPrototypeNode 0x118ab0b40 [rc=67] root nsXULPrototypeNode 0x1174643c0 [rc=5] root nsXULPrototypeNode 0x118ab0f80 [rc=5] root nsXULPrototypeNode 0x118f68000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/text.xml Roots: 1 0x118f5f1a0 [rc=157] root nsXBLDocumentInfo 0x119bea000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/menu.xml Roots: 22 0x119974b00 [rc=207] root nsXBLDocumentInfo 0x119d96880 [rc=3] root nsXULPrototypeNode 0x119d2ffc0 [rc=2] root nsXULPrototypeNode 0x119d2f980 [rc=17] root nsXULPrototypeNode 0x119d2f680 [rc=35] root nsXULPrototypeNode 0x119d2fbc0 [rc=17] root nsXULPrototypeNode 0x119d96980 [rc=3] root nsXULPrototypeNode 0x119d96100 [rc=2] root nsXULPrototypeNode 0x119d2fac0 [rc=17] root nsXULPrototypeNode 0x119d2f780 [rc=35] root nsXULPrototypeNode 0x119d96740 [rc=3] root nsXULPrototypeNode 0x119d96900 [rc=3] root nsXULPrototypeNode 0x119d96a40 [rc=3] root nsXULPrototypeNode 0x119d2fe40 [rc=2] root nsXULPrototypeNode 0x119d96080 [rc=2] root nsXULPrototypeNode 0x119d2fa40 [rc=17] root nsXULPrototypeNode 0x119d2f700 [rc=35] root nsXULPrototypeNode 0x119d2f840 [rc=35] root nsXULPrototypeNode 0x119d967c0 [rc=3] root nsXULPrototypeNode 0x119d96ac0 [rc=3] root nsXULPrototypeNode 0x119d2fec0 [rc=2] root nsXULPrototypeNode 0x119d2f8c0 [rc=35] root nsXULPrototypeNode 0x118f67800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/button.xml Roots: 3 0x118f4c830 [rc=31] root nsXBLDocumentInfo 0x118f59e80 [rc=4] root nsGenericElement (XBL) children chrome://global/content/bindings/button.xml 0x118f58dc0 [rc=2] root nsXULPrototypeNode 0x1199c6000 [rc=2] nsDocument normal ([none]) chrome://browser/content/tabbrowser.xml Roots: 25 0x119a1a880 [rc=25] root nsXBLDocumentInfo 0x119a8c100 [rc=2] root nsXULPrototypeNode 0x11999fba0 [rc=13] root nsNodeInfo (XBL) inherits 0x119ae2580 [rc=4] root nsXULPrototypeNode 0x12227c1a0 [rc=6] root nsGenericElement (XUL) hbox class='tab-content' chrome://browser/content/browser.xul 0x119ae2540 [rc=4] root nsXULPrototypeNode 0x119ae24c0 [rc=4] root nsXULPrototypeNode 0x119ae2480 [rc=4] root nsXULPrototypeNode 0x119ae2200 [rc=4] root nsXULPrototypeNode 0x119ae22c0 [rc=4] root nsXULPrototypeNode 0x119ae2380 [rc=4] root nsXULPrototypeNode 0x119ae2400 [rc=4] root nsXULPrototypeNode 0x119ae2a80 [rc=2] root nsXULPrototypeNode 0x119ae25c0 [rc=4] root nsXULPrototypeNode 0x119a8ca80 [rc=2] root nsXULPrototypeNode 0x119ae2a00 [rc=2] root nsXULPrototypeNode 0x119a8ca00 [rc=2] root nsXULPrototypeNode 0x119a8cb40 [rc=2] root nsXULPrototypeNode 0x119ae2180 [rc=4] root nsXULPrototypeNode 0x119a8c2c0 [rc=2] root nsXULPrototypeNode 0x119a8cc00 [rc=2] root nsXULPrototypeNode 0x119a8cc40 [rc=2] root nsXULPrototypeNode 0x119a8c080 [rc=2] root nsXULPrototypeNode 0x119a8c180 [rc=2] root nsXULPrototypeNode 0x119a8c240 [rc=2] root nsXULPrototypeNode 0x1199c4800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/scrollbox.xml Roots: 5 0x1199ae150 [rc=14] root nsXBLDocumentInfo 0x1199bf940 [rc=2] root nsXULPrototypeNode 0x1199bf2c0 [rc=4] root nsXULPrototypeNode 0x1199bf840 [rc=2] root nsXULPrototypeNode 0x1199bfa00 [rc=2] root nsXULPrototypeNode 0x119ace800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/splitter.xml Roots: 1 0x119a57100 [rc=4] root nsXBLDocumentInfo 0x1193fd800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/general.xml Roots: 5 0x118a92830 [rc=418] root nsXBLDocumentInfo 0x118a7e580 [rc=3] root nsGenericElement (XBL) children chrome://global/content/bindings/general.xml 0x118ac7340 [rc=2] root nsXULPrototypeNode 0x118ac78c0 [rc=9] root nsXULPrototypeNode 0x118ac7380 [rc=2] root nsXULPrototypeNode 0x118fdc800 [rc=2] nsDocument normal ([none]) chrome://browser/content/search/search.xml Roots: 12 0x117630830 [rc=7] root nsXBLDocumentInfo 0x1199c0600 [rc=2] root nsXULPrototypeNode 0x1199c06c0 [rc=2] root nsXULPrototypeNode 0x1199c0700 [rc=2] root nsXULPrototypeNode 0x1199c0b80 [rc=2] root nsXULPrototypeNode 0x1199c0880 [rc=2] root nsXULPrototypeNode 0x1199c0780 [rc=2] root nsXULPrototypeNode 0x1199c0bc0 [rc=2] root nsXULPrototypeNode 0x1199c0980 [rc=2] root nsXULPrototypeNode 0x1199c0a00 [rc=2] root nsXULPrototypeNode 0x1199c0a80 [rc=2] root nsXULPrototypeNode 0x1199c0b00 [rc=2] root nsXULPrototypeNode 0x118fde000 [rc=2] nsDocument normal ([none]) chrome://browser/content/places/menu.xml Roots: 5 0x1199a3d30 [rc=6] root nsXBLDocumentInfo 0x1199dd200 [rc=4] root nsXULPrototypeNode 0x1199cbfc0 [rc=4] root nsXULPrototypeNode 0x1199dd040 [rc=4] root nsXULPrototypeNode 0x1199dd100 [rc=4] root nsXULPrototypeNode 0x122606000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/listbox.xml Roots: 1 0x122875420 [rc=23] root nsXBLDocumentInfo 0x1199c9800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/tabbox.xml Roots: 1 0x119a853d0 [rc=16] root nsXBLDocumentInfo 0x122680000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/richlistbox.xml Roots: 2 0x122592a60 [rc=18] root nsXBLDocumentInfo 0x1229f0200 [rc=2] root nsXULPrototypeNode 0x11745d000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/stringbundle.xml Roots: 1 0x117459970 [rc=18] root nsXBLDocumentInfo 0x1195b9800 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/textbox.xml Roots: 10 0x118f5f740 [rc=12] root nsXBLDocumentInfo 0x116f8de40 [rc=3] root nsXULPrototypeNode 0x116f8dec0 [rc=3] root nsXULPrototypeNode 0x116f8df80 [rc=3] root nsXULPrototypeNode 0x116f8dfc0 [rc=3] root nsXULPrototypeNode 0x118fd6dc0 [rc=3] root nsXULPrototypeNode 0x118fe9040 [rc=3] root nsXULPrototypeNode 0x116f8df00 [rc=3] root nsXULPrototypeNode 0x116f8df40 [rc=3] root nsXULPrototypeNode 0x118fe9080 [rc=3] root nsXULPrototypeNode 0x1195b9000 [rc=2] nsDocument normal ([none]) chrome://global/content/bindings/autocomplete.xml Roots: 30 0x1195ef100 [rc=36] root nsXBLDocumentInfo 0x118f1be00 [rc=13] root nsXULPrototypeNode 0x118f29080 [rc=3] root nsGenericElement (XBL) children chrome://global/content/bindings/autocomplete.xml 0x118f1b880 [rc=13] root nsXULPrototypeNode 0x1193f1780 [rc=2] root nsXULPrototypeNode 0x1193f18c0 [rc=2] root nsXULPrototypeNode 0x118f1b580 [rc=2] root nsXULPrototypeNode 0x118f1b6c0 [rc=13] root nsXULPrototypeNode 0x118f1bcc0 [rc=13] root nsXULPrototypeNode 0x118f1ba80 [rc=13] root nsXULPrototypeNode 0x1193f1980 [rc=2] root nsXULPrototypeNode 0x1193f19c0 [rc=2] root nsXULPrototypeNode 0x118f1b7c0 [rc=13] root nsXULPrototypeNode 0x118f1ba00 [rc=13] root nsXULPrototypeNode 0x118f1bfc0 [rc=13] root nsXULPrototypeNode 0x118f1b940 [rc=13] root nsXULPrototypeNode 0x118f1bb40 [rc=13] root nsXULPrototypeNode 0x118f1bbc0 [rc=13] root nsXULPrototypeNode 0x118f1bec0 [rc=13] root nsXULPrototypeNode 0x118f1bf80 [rc=13] root nsXULPrototypeNode 0x118f1bc40 [rc=13] root nsXULPrototypeNode 0x118f1bdc0 [rc=13] root nsXULPrototypeNode 0x118f1bac0 [rc=13] root nsXULPrototypeNode 0x118f1b540 [rc=2] root nsXULPrototypeNode 0x1193f1f40 [rc=2] root nsXULPrototypeNode 0x118f1bd40 [rc=13] root nsXULPrototypeNode 0x118f74080 [rc=13] root nsXULPrototypeNode 0x1193f1fc0 [rc=2] root nsXULPrototypeNode 0x118f1b1c0 [rc=2] root nsXULPrototypeNode 0x118f1b080 [rc=2] root nsXULPrototypeNode

smaug: That log seems kinda... crazy. What's the chance that about:cc is lying to ttaubert?

For future reference: the two addons Tim tested with were: * about:cc * https://addons.mozilla.org/en-US/firefox/addon/facebook-auto-logout/

(In reply to Blair McBride (:Unfocused) from comment #3) > smaug: That log seems kinda... crazy. What's the chance that about:cc is > lying to ttaubert? Well, about:cc just reads cc log. Another way to check it is to use the log files https://wiki.mozilla.org/Performance:Leak_Tools#Cycle_collector_heap_dump One should probably run cycle collector few times. Looks like the documents are all XBL documents. I assume installing a new addon may invalidate xul cache. Do we not release the old cached xbl documents or something? Or do we re-load some xbl documents we shouldn't?

Also, in this case it may not be a really a leak, but if we flush XUL cache, XBL documents which used to be in the cache can't be optimized out from CC graph anymore.

(In reply to Tim Taubert [:ttaubert] from comment #1) > Installing an add-on via AMO leaks a lot less: > > 0x1237c6000 [rc=3] nsDocument normal (xhtml) > https://addons.mozilla.org/de/firefox/addon/facebook-auto-logout/ > Roots: 1 > 0x1478efe10 [rc=2] root nsXPCWrappedJS (nsISupports) This is probably bug 728414

I don't see anything obvious here for [Snappy]

This kinds of leaks increase CC times.

Per policy at https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Inactive_Bugs. If this bug is not an enhancement request or a bug not present in a supported release of Firefox, then it may be reopened.