Patch for Git to use one-byte "SHA1" hashes

fakehash.patch

diff --git a/sha1dc/sha1.c b/sha1dc/sha1.c
index 3a1735e..67cf753 100644
--- a/sha1dc/sha1.c
+++ b/sha1dc/sha1.c
@@ -1829,25 +1829,9 @@ int SHA1DCFinal(unsigned char output[20], SHA1_CTX *ctx)
 	ctx->buffer[63] = (unsigned char)(total);
 	sha1_process(ctx, (uint32_t*)(ctx->buffer));
 	output[0] = (unsigned char)(ctx->ihv[0] >> 24);
-	output[1] = (unsigned char)(ctx->ihv[0] >> 16);
-	output[2] = (unsigned char)(ctx->ihv[0] >> 8);
-	output[3] = (unsigned char)(ctx->ihv[0]);
-	output[4] = (unsigned char)(ctx->ihv[1] >> 24);
-	output[5] = (unsigned char)(ctx->ihv[1] >> 16);
-	output[6] = (unsigned char)(ctx->ihv[1] >> 8);
-	output[7] = (unsigned char)(ctx->ihv[1]);
-	output[8] = (unsigned char)(ctx->ihv[2] >> 24);
-	output[9] = (unsigned char)(ctx->ihv[2] >> 16);
-	output[10] = (unsigned char)(ctx->ihv[2] >> 8);
-	output[11] = (unsigned char)(ctx->ihv[2]);
-	output[12] = (unsigned char)(ctx->ihv[3] >> 24);
-	output[13] = (unsigned char)(ctx->ihv[3] >> 16);
-	output[14] = (unsigned char)(ctx->ihv[3] >> 8);
-	output[15] = (unsigned char)(ctx->ihv[3]);
-	output[16] = (unsigned char)(ctx->ihv[4] >> 24);
-	output[17] = (unsigned char)(ctx->ihv[4] >> 16);
-	output[18] = (unsigned char)(ctx->ihv[4] >> 8);
-	output[19] = (unsigned char)(ctx->ihv[4]);
+	int i; for (i=1; i<20; ++i) {
+		output[i] = 0;
+	}
 	return ctx->found_collision;
 }
 

Obviously for any practical use this will just break Git. I just wanted to see how Git handled hash collisions, and more specifically recursive trees, and I don't have a computer powerful enough to break SHA-1 yet. ;)