[Lldb-commits] [lldb] [lldb] Skip remote PutFile when MD5 hashes equal (PR #88812)

[Anthony Ha via lldb-commits]

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@@ -3433,8 +3433,40 @@ bool GDBRemoteCommunicationClient::CalculateMD5(
       return false;
     if (response.Peek() && *response.Peek() == 'x')
       return false;
-    low = response.GetHexMaxU64(false, UINT64_MAX);
-    high = response.GetHexMaxU64(false, UINT64_MAX);
+
+    // GDBRemoteCommunicationServerCommon::Handle_vFile_MD5 concatenates low and
+    // high hex strings. We can't use response.GetHexMaxU64 because that can't
+    // handle the concatenated hex string. What would happen is parsing the low
+    // would consume the whole response packet - which is a bug. Instead, we get
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Awfa wrote:

`response.GetHexMaxU64` consumes the response stream until a non-valid hex character is encountered.

This is just the wrong function to use because the server returns both the low/high parts concatenated. When it was used, what would happen is `low = response.GetHexMaxU64...` would consume the whole packet, when it should just be consuming the first half of it. This also leads to `high` being set to 0 because `low` consumed the entire packet.

This part of the patch isn't a workaround, it's the fix. This fixes the client so it can correctly parse the server's response.

https://github.com/llvm/llvm-project/pull/88812