base: Fix double truncation in DynamicStringWriter and FixedStringWriter#5438
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backes wants to merge 3 commits intogoogle:mainfrom
Open
base: Fix double truncation in DynamicStringWriter and FixedStringWriter#5438backes wants to merge 3 commits intogoogle:mainfrom
backes wants to merge 3 commits intogoogle:mainfrom
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When formatting large doubles like 1e100, %lf produces a fixed-point representation that can be very long. In DynamicStringWriter, this was truncated to 31 characters because of the 32-byte fixed buffer in StackString. This CL changes the format from %lf to %.16g, which uses scientific notation for large and small exponents, ensuring it fits in the fixed buffer and preserving double precision. This fixes an issue where V8's JsonIntegrationTest was failing when using Perfetto's JSON exporter. Bug: 382242434
LalitMaganti
approved these changes
Apr 13, 2026
Author
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Thanks for the quick review! Feel free to merge, I don't have permissions! |
sashwinbalaji
approved these changes
Apr 13, 2026
LalitMaganti
approved these changes
Apr 13, 2026
Member
|
Seems like there's a UI test failure. |
Author
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Oh, yes, we print a more precise value now. New: |
Author
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I see that the screenshot itself is not checked in, there's just a sha256 hash in |
auto-merge was automatically disabled
April 13, 2026 14:52
Head branch was pushed to by a user without write access
Author
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Found Should work now. |
Author
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Merge conflict :/ |
Member
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tools/run-integrationtests --rebaseline |
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When formatting large doubles like 1e100, %lf produces a fixed-point representation that can be very long. In DynamicStringWriter, this was truncated to 31 characters because of the 32-byte fixed buffer in StackString.
This CL changes the format from %lf to %.16g, which uses scientific notation for large and small exponents, ensuring it fits in the fixed buffer and preserving double precision.
This fixes an issue where V8's JsonIntegrationTest was failing when using Perfetto's JSON exporter (see https://crrev.com/c/7748468).
Bug: b/502067293