Why does it remove 'amp;' from the SEARCH code during the apply_diff process?

[maskelihileci]

App Version

v3.8.4

API Provider

Google Gemini

Model Used

Gemini 2.5 Pro Preview 05-06

🔁 Steps to Reproduce

---

Title: apply_diff fails due to unexpected source modification by Roo Code

I've been tracking persistent performance issues with the apply_diff feature when using Gemini-based models, particularly when reviewing pull requests. There are several causes, but one frequent problem is that the AI sometimes uses the SEARCH block to search for the already-modified code, which obviously fails.

However, this time, the failure wasn't due to AI logic or reasoning mistakes.

This time, it seems Roo Code itself arbitrarily modified the code that the AI was trying to search for. The AI-generated SEARCH block was correct, but the apply_diff failed because Roo Code had internally altered the ampersand in a comment (& became &), causing a mismatch.

Here is the input prompt and diff that triggered the error:

An error occurred during the `apply_diff` operation. It seems that the comment line in the `SEARCH` block contained `&`, which I wrote as `&`. This minor difference prevented a 100% match.

Now, I will retry the `apply_diff` operation with the correct `SEARCH` and `REPLACE` blocks, including the intended logical update: if the value read from the pointer is greater than or equal to `ImageBase`, it is assumed to be a VA and converted to an RVA; otherwise, it is treated directly as an RVA.

<apply_diff>
<path>pe_utils.c</path>
<diff>
<<<<<<< SEARCH
:start_line:1802
-------
    // Adım 4: Pointer değerini (işaret edilen RVA) oku
    if (dwPointerHolderOffset + sizeof(DWORD) > FileSize) {
        StringCchPrintfW(wszLog, _countof(wszLog),
            L"VerifyPeData [%s]: Read out of bounds for pointer value at offset 0x%X.",
            Item->Description ? Item->Description : L"N/A", dwPointerHolderOffset);
        DebugLog(wszLog);
        return VERIFICATION_FAILED_READ_POINTER_VALUE;
    }
    dwPointedToRva = *(PDWORD)(FileBuffer + dwPointerHolderOffset);
    StringCchPrintfW(wszLog, _countof(wszLog),
        L"VerifyPeData [%s]: Pointer at RVA 0x%X (Offset 0x%X) in section '%.8hs' points to RVA 0x%X.",
        Item->Description ? Item->Description : L"N/A", Item->RvaOfPointerHolder, dwPointerHolderOffset, Item->PointerHolderSectionName, dwPointedToRva);
    DebugLog(wszLog);

    // Adım 5 &amp; 6: İşaret edilen verinin bölümünü bul ve doğrula
=======
    // Adım 4: Pointer değerini (işaret edilen RVA veya VA) oku
    if (dwPointerHolderOffset + sizeof(DWORD) > FileSize) {
        StringCchPrintfW(wszLog, _countof(wszLog),
            L"VerifyPeData [%s]: Read out of bounds for pointer value at offset 0x%X.",
            Item->Description ? Item->Description : L"N/A", dwPointerHolderOffset);
        DebugLog(wszLog);
        return VERIFICATION_FAILED_READ_POINTER_VALUE;
    }
    DWORD valueReadFromPointer = *(PDWORD)(FileBuffer + dwPointerHolderOffset);
    ULONGLONG imageBase = NtHeaders->OptionalHeader.ImageBase;

    // Eğer okunan değer (valueReadFromPointer), geçerli bir ImageBase'den büyük veya eşitse,
    // bunun bir Sanal Adres (VA) olduğunu ve RVA'ya çevrilmesi gerektiğini varsay.
    // Aksi halde, zaten bir RVA (veya ImageBase'e göre küçük bir ofset/RVA) olduğunu varsay.
    if (imageBase != 0 && valueReadFromPointer >= imageBase) {
        dwPointedToRva = (DWORD)(valueReadFromPointer - imageBase);
        StringCchPrintfW(wszLog, _countof(wszLog),
            L"VerifyPeData [%s]: Pointer at RVA 0x%X (Offset 0x%X) in '%.8hs' holds VA 0x%X, converted to RVA 0x%X.",
            Item->Description ? Item->Description : L"N/A", Item->RvaOfPointerHolder, dwPointerHolderOffset, pPointerHolderSection->Name, valueReadFromPointer, dwPointedToRva);
        DebugLog(wszLog);
    } else {
        dwPointedToRva = valueReadFromPointer; // Zaten RVA veya ImageBase'siz bir ofset/RVA olarak kabul et.
        StringCchPrintfW(wszLog, _countof(wszLog),
            L"VerifyPeData [%s]: Pointer at RVA 0x%X (Offset 0x%X) in section '%.8hs' points to RVA 0x%X (treated as RVA or offset).",
            Item->Description ? Item->Description : L"N/A", Item->RvaOfPointerHolder, dwPointerHolderOffset, pPointerHolderSection->Name, dwPointedToRva);
        DebugLog(wszLog);
    }

    // Adım 5 &amp; 6: İşaret edilen verinin bölümünü bul ve doğrula
>>>>>>> REPLACE
</diff>
</apply_diff>

Expected behavior:
The apply_diff mechanism should not internally alter the SEARCH block during application — especially for non-semantic differences like HTML entity decoding in comments (& → &).

Actual behavior:
The AI provided a valid and accurate diff, but Roo Code modified the input SEARCH block internally, preventing a match and causing the patch to fail.

Suggestion:
Please ensure that the raw diff (as provided) is used verbatim during comparison and patch application. Any transformation (like entity decoding) should only be done if explicitly instructed by the prompt or controlled via a toggle.

---

💥 Outcome Summary

The apply_diff operation is not applied with a Similarity Score of 99%.

📄 Relevant Logs or Errors (Optional)

Hata çıktısı hepsini atamıyorum kişisel bilgiler nedeniyle ama hatanın ne olduğunu anlaşılıyor.

[apply_diff for 'pe_utils.c'] Result:
<error_details>
No sufficiently similar match found at line: 1802 (99% similar, needs 100%)

Debug Info:
- Similarity Score: 99%
- Required Threshold: 100%
- Search Range: starting at line 1802
- Tried both standard and aggressive line number stripping
- Tip: Use the read_file tool to get the latest content of the file before attempting to use the apply_diff tool again, as the file content may have changed

Search Content:
    // Adım 4: Pointer değerini (işaret edilen RVA) oku
    if (dwPointerHolderOffset + sizeof(DWORD) > FileSize) {
        StringCchPrintfW(wszLog, _countof(wszLog),
            L"VerifyPeData [%s]: Read out of bounds for pointer value at offset 0x%X.",
            Item->Description ? Item->Description : L"N/A", dwPointerHolderOffset);
        DebugLog(wszLog);
        return VERIFICATION_FAILED_READ_POINTER_VALUE;
    }
    dwPointedToRva = *(PDWORD)(FileBuffer + dwPointerHolderOffset);
    StringCchPrintfW(wszLog, _countof(wszLog),
        L"VerifyPeData [%s]: Pointer at RVA 0x%X (Offset 0x%X) in section '%.8hs' points to RVA 0x%X.",
        Item->Description ? Item->Description : L"N/A", Item->RvaOfPointerHolder, dwPointerHolderOffset, Item->PointerHolderSectionName, dwPointedToRva);
    DebugLog(wszLog);

    // Adım 5 & 6: İşaret edilen verinin bölümünü bul ve doğrula

Best Match Found:
1802 |     // Adım 4: Pointer değerini (işaret edilen RVA) oku
1803 |     if (dwPointerHolderOffset + sizeof(DWORD) > FileSize) {
1804 |         StringCchPrintfW(wszLog, _countof(wszLog),
1805 |             L"VerifyPeData [%s]: Read out of bounds for pointer value at offset 0x%X.",
1806 |             Item->Description ? Item->Description : L"N/A", dwPointerHolderOffset);
1807 |         DebugLog(wszLog);
1808 |         return VERIFICATION_FAILED_READ_POINTER_VALUE;
1809 |     }
1810 |     dwPointedToRva = *(PDWORD)(FileBuffer + dwPointerHolderOffset);
1811 |     StringCchPrintfW(wszLog, _countof(wszLog),
1812 |         L"VerifyPeData [%s]: Pointer at RVA 0x%X (Offset 0x%X) in section '%.8hs' points to RVA 0x%X.",
1813 |         Item->Description ? Item->Description : L"N/A", Item->RvaOfPointerHolder, dwPointerHolderOffset, Item->PointerHolderSectionName, dwPointedToRva);
1814 |     DebugLog(wszLog);
1815 | 
1816 |     // Adım 5 &amp; 6: İşaret edilen verinin bölümünü bul ve doğrula


Original Content:
1802 |     // Adım 4: Pointer değerini (işaret edilen RVA) oku
1803 |     if (dwPointerHolderOffset + sizeof(DWORD) > FileSize) {
1804 |         StringCchPrintfW(wszLog, _countof(wszLog),
1805 |             L"VerifyPeData [%s]: Read out of bounds for pointer value at offset 0x%X.",
1806 |             Item->Description ? Item->Description : L"N/A", dwPointerHolderOffset);
1807 |         DebugLog(wszLog);
1808 |         return VERIFICATION_FAILED_READ_POINTER_VALUE;
1809 |     }
1810 |     dwPointedToRva = *(PDWORD)(FileBuffer + dwPointerHolderOffset);
1811 |     StringCchPrintfW(wszLog, _countof(wszLog),
1812 |         L"VerifyPeData [%s]: Pointer at RVA 0x%X (Offset 0x%X) in section '%.8hs' points to RVA 0x%X.",
1813 |         Item->Description ? Item->Description : L"N/A", Item->RvaOfPointerHolder, dwPointerHolderOffset, Item->PointerHolderSectionName, dwPointedToRva);
1814 |     DebugLog(wszLog);
1815 | 
1816 |     // Adım 5 &amp; 6: İşaret edilen verinin bölümünü bul ve doğrula

</error_details>
<environment_details>
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# Current Mode
<slug>code</slug>
<name>💻 Code</name>
<model>human-relay</model>
<role>You are Roo, a highly skilled software engineer with extensive knowledge in many programming languages, frameworks, design patterns, and best practices.</role>
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</environment_details>

[dosubot]

Hi @maskelihileci! I'm Dosu and I’m helping the Roo-Code team.

Yaptığım kapsamlı dokümantasyon araştırmasında, Roo Code'un apply_diff aracının SEARCH bloğu üzerinde neden HTML entity dönüşümü (ör. & → &) yaptığına dair herhangi bir bilgiye ulaşamadım. Resmî dokümana göre, apply_diff aracı tam eşleşme gerektiriyor ve Levenshtein tabanlı fuzzy matching algoritması kullanıyor, ancak SEARCH bloğu üzerinde HTML entity çözümlemesi veya otomatik dönüşüm yapıldığına dair bir açıklama yok. Dokümanlarda bu davranışın nedeni veya bir ayarı da belirtilmemiş durumda (kaynak 1).

Yani, Roo Code'un apply_diff işlemi sırasında SEARCH bloğundaki & ifadesini neden otomatik olarak & karakterine dönüştürdüğü veya bu davranışın nasıl devre dışı bırakılabileceği konusunda elimde kesin bir bilgi yok. Bu, dokümantasyonda açıkça ele alınmamış bir durum.

Eğer bu davranış sizin için kritikse, Roo Code'un daha güncel sürümlerinde veya topluluk kanallarında bu konuda bir değişiklik ya da tartışma olup olmadığını takip etmek faydalı olabilir. Şu anki bilgiler ışığında, apply_diff aracının SEARCH bloğunu olduğu gibi, yani hiçbir dönüşüm yapmadan kullanması beklenir; fakat pratikte sizinki gibi bir sorun yaşanıyorsa, bu muhtemelen bir hata veya beklenmeyen bir ön işleme adımından kaynaklanıyor olabilir.

To reply, just mention my name @dosu.

---

^{How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other}   

[maskelihileci]

@dosu

When we provide the command below as input, it doesn't accept it and returns the following error.
As you can see, it removed the &amp part. :)

🔧 Input Command

<apply_diff>
  <path>pe_utils.c</path>
  <diff>
<<<<<<< SEARCH
:start_line:1753
-------
void Hello()
{
DebugLog("Hello"); // Adım 5 &amp; 6: Hello

}
=======
void Word()
{
DebugLog("Word"); // Adım 5 &amp; 6: Word

}
>>>>>>> REPLACE
  </diff>
</apply_diff>

🧨 Result

[apply_diff for 'pe_utils.c'] Result:
<error_details>
No sufficiently similar match found at line: 1753 (93% similar, needs 100%)

Debug Info:
- Similarity Score: 93%
- Required Threshold: 100%
- Search Range: starting at line 1753
- Tried both standard and aggressive line number stripping
- Tip: Use the read_file tool to get the latest content of the file before attempting to use the apply_diff tool again, as the file content may have changed

Search Content:
void Hello()
{
DebugLog("Hello"); // Adım 5 & 6: Hello

}

Best Match Found:
1753 | void Hello()
1754 | {
1755 | DebugLog("Hello"); // Adım 5 &amp; 6: Hello
1756 | 
1757 | }

Original Content:
1752 | 
1753 | void Hello()
1754 | {
1755 | DebugLog("Hello"); // Adım 5 &amp; 6: Hello
1756 | 
1757 | }
1758 | 
</error_details>

[daniel-lxs]

Probably introduced by #2694

[maskelihileci]

Muhtemelen #2694 tarafından tanıtıldı

Yes, most likely the problem is caused by this. A different method or new controls are needed to address the escape issues.