Fix a bad assert in hsRAMStream #1591
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This was added because UBSan was warning that we were calling memcpy with a null destination, and while that is technically true, it was also a no-op because it was copying 0 bytes. A null buffer gets properly resized with the data in the next step, so this is actually expected behaviour that is broken by asserting too early. Instead, detect the cases where we're calling memcpy with actual data, and assert in those cases that the RAMStream buffer is non-null.
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I added a (pretty minimal) unit test here that would trigger the previous assert, and is working now with the modified asserts. |
colincornaby
approved these changes
Jun 2, 2024
Hoikas
reviewed
Jun 2, 2024
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| TEST(hsRAMStream, initializeBufferOnFirstWrite) | ||
| { | ||
| const char* str = "hsRAMStream initializeBufferOnFirstWrite"; |
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| const char* str = "hsRAMStream initializeBufferOnFirstWrite"; | |
| constexpr std::string_view str = "hsRAMStream initializeBufferOnFirstWrite"; |
| hsRAMStream s; | ||
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| s.WriteSafeString(str); | ||
| EXPECT_EQ(s.GetPosition(), strlen(str) + 2); |
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| EXPECT_EQ(s.GetPosition(), strlen(str) + 2); | |
| EXPECT_EQ(s.GetPosition(), str.size() + 2); |
| EXPECT_EQ(s.GetPosition(), strlen(str) + 2); | ||
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| s.WriteLE32(1); | ||
| EXPECT_EQ(s.GetPosition(), strlen(str) + 2 + 4); |
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| EXPECT_EQ(s.GetPosition(), strlen(str) + 2 + 4); | |
| EXPECT_EQ(s.GetPosition(), str.size() + 2 + 4); |
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| s.Skip(-4); | ||
| s.WriteLE32(5); | ||
| EXPECT_EQ(s.GetPosition(), strlen(str) + 2 + 4); |
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| EXPECT_EQ(s.GetPosition(), strlen(str) + 2 + 4); | |
| EXPECT_EQ(s.GetPosition(), str.size() + 2 + 4); |
| *==LICENSE==*/ | ||
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| #include <gtest/gtest.h> | ||
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| #include <string_view> | |
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This was added because UBSan was warning that we were calling memcpy with a null destination, and while that is technically true, it was also a no-op because it was copying 0 bytes. A null buffer gets properly resized with the data in the next step, so this is actually expected behaviour that is broken by asserting too early.
Instead, detect the cases where we're calling memcpy with actual data, and assert in those cases that the RAMStream buffer is non-null.