Looks like the same crash as bug 719114. https://tbpl.mozilla.org/php/getParsedLog.php?id=10886138&tree=Mozilla-Inbound Rev4 MacOSX Snow Leopard 10.6 mozilla-inbound debug test jsreftest on 2012-04-13 13:36:14 PDT for push 4a6a021e38ca REFTEST INFO | Loading a blank page ++DOMWINDOW == 83 (0x14169a448) [serial = 5681] [outer = 0x11a287ff0] REFTEST TEST-START | file:///Users/cltbld/talos-slave/test/build/jsreftest/tests/jsreftest.html?test=js1_8/regress/regress-471373.js | 3028 / 3386 (89%) ++DOMWINDOW == 84 (0x142a15de8) [serial = 5682] [outer = 0x11a287ff0] BUGNUMBER: 471373 STATUS: TM: do not assert: (size_t)(regs.pc - script->code) < script->length TEST-UNEXPECTED-FAIL | file:///Users/cltbld/talos-slave/test/build/jsreftest/tests/jsreftest.html?test=js1_8/regress/regress-471373.js | Exited with code 1 during test run INFO | automation.py | Application ran for: 0:11:16.043941 INFO | automation.py | Reading PID log: /var/folders/Hs/HsDn6a9SG8idoIya6p9mtE+++TI/-Tmp-/tmp2ZD1IPpidlog Downloading symbols from: http://ftp.mozilla.org/pub/mozilla.org/firefox/tinderbox-builds/mozilla-inbound-macosx64-debug/1334348593/firefox-14.0a1.en-US.mac64.crashreporter-symbols.zip PROCESS-CRASH | file:///Users/cltbld/talos-slave/test/build/jsreftest/tests/jsreftest.html?test=js1_8/regress/regress-471373.js | application crashed (minidump found) Crash dump filename: /var/folders/Hs/HsDn6a9SG8idoIya6p9mtE+++TI/-Tmp-/tmpBTBIF5/minidumps/7F308C49-E6D0-4A43-915E-4BA4B8B840D9.dmp Operating system: Mac OS X 10.6.8 10K549 CPU: amd64 family 6 model 23 stepping 10 2 CPUs Crash reason: EXC_BAD_ACCESS / KERN_INVALID_ADDRESS Crash address: 0x6523000 Thread 0 (crashed) 0 XUL!js::GCMarker::processMarkStackTop [jsgc.h : 984 + 0x0] rbx = 0x06523000 r12 = 0x06523800 r13 = 0x51ec5c01 r14 = 0x00000000 r15 = 0x5fbfa620 rip = 0x03a24b48 rsp = 0x5fbfa500 rbp = 0x5fbfa590 Found by: given as instruction pointer in context 1 XUL!js::GCMarker::drainMarkStack [jsgcmark.cpp : 1129 + 0xa] rbx = 0x05dcd228 r12 = 0x5fbfa620 r13 = 0x05dcd260 r14 = 0x05dcd000 r15 = 0x05dcd000 rip = 0x03a1c99b rsp = 0x5fbfa5a0 rbp = 0x5fbfa5c0 Found by: call frame info 2 XUL!GCCycle [jsgc.cpp : 3246 + 0x12] rbx = 0x210d4d40 r12 = 0x00000014 r13 = 0x40daa000 r14 = 0x210d4c10 r15 = 0x05dcd000 rip = 0x03a074be rsp = 0x5fbfa5d0 rbp = 0x5fbfa6b0 Found by: call frame info 3 XUL!Collect [jsgc.cpp : 3689 + 0x11] rbx = 0x05dcd318 r12 = 0x05dcd000 r13 = 0x05dcd9f8 r14 = 0x00000001 r15 = 0x5fbfa6e0 rip = 0x03a081fe rsp = 0x5fbfa6c0 rbp = 0x5fbfa720 Found by: call frame info 4 XUL!js_InvokeOperationCallback [jscntxt.cpp : 870 + 0x11] rbx = 0x00000001 r12 = 0x05dcd000 r13 = 0x1a288480 r14 = 0x2613f560 r15 = 0x05ffb160 rip = 0x039a61a2 rsp = 0x5fbfa730 rbp = 0x5fbfa750 Found by: call frame info 5 XUL!js_HandleExecutionInterrupt [jscntxt.cpp : 886 + 0x4] rbx = 0x00000001 r12 = 0x0000006d r13 = 0x05ffb160 r14 = 0x2613f560 r15 = 0x05ffb160 rip = 0x039a61c7 rsp = 0x5fbfa760 rbp = 0x5fbfa760 Found by: call frame info 6 XUL!js::Interpret [jsinterp.cpp : 1796 + 0x7] rbx = 0x00000001 r12 = 0x0000006d r13 = 0x05ffb160 r14 = 0x2613f560 r15 = 0x05ffb160 rip = 0x03a6b299 rsp = 0x5fbfa770 rbp = 0x5fbfb370 Found by: call frame info 7 XUL!js::RunScript [jsinterp.cpp : 475 + 0xc] rbx = 0x428ee240 r12 = 0x1a288480 r13 = 0x05ffb160 r14 = 0x2613f560 r15 = 0x05ffb160 rip = 0x03a758ed rsp = 0x5fbfb380 rbp = 0x5fbfb3d0 Found by: call frame info 8 XUL!SendToGenerator [jsiter.cpp : 1582 + 0x15] rbx = 0x00000000 r12 = 0x1a288638 r13 = 0x1a288480 r14 = 0x41645120 r15 = 0x05ffb160 rip = 0x03a8253d rsp = 0x5fbfb3e0 rbp = 0x5fbfb4e0 Found by: call frame info 9 XUL!generator_op [jsiter.cpp : 1689 + 0x29] rbx = 0x26145520 r12 = 0x41645120 r13 = 0x00000000 r14 = 0x05ffb150 r15 = 0x00000000 rip = 0x03a8342f rsp = 0x5fbfb4f0 rbp = 0x5fbfb5b0

This bug was observed only on one or more of the six machines listed in bug 787281 comment 11, which seem likely to have bad memory, disk, or other hardware problem, based on the rate of failures on those machines and the types of failures observed. Therefore I'm marking this bug invalid, though it should be reopened if it occurs on other (more reliable) hardware.