Add git.Blob Fuzz Target

fuzzing/dictionaries/fuzz_blob.dict

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+"\\377\\377\\377\\377\\377\\377\\377\\377" 

fuzzing/fuzz-targets/fuzz_blob.py

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+import atheris
+import sys
+import os
+import tempfile
+
+if getattr(sys, "frozen", False) and hasattr(sys, "_MEIPASS"):
+    path_to_bundled_git_binary = os.path.abspath(os.path.join(os.path.dirname(__file__), "git"))
+    os.environ["GIT_PYTHON_GIT_EXECUTABLE"] = path_to_bundled_git_binary
+
+with atheris.instrument_imports():
+    import git
+
+
+def TestOneInput(data):
+    fdp = atheris.FuzzedDataProvider(data)
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        repo = git.Repo.init(path=temp_dir)
+        binsha = fdp.ConsumeBytes(20)
+        mode = fdp.ConsumeInt(fdp.ConsumeIntInRange(0, fdp.remaining_bytes()))
+        path = fdp.ConsumeUnicodeNoSurrogates(fdp.remaining_bytes())
+
+        try:
+            blob = git.Blob(repo, binsha, mode, path)
+        except AssertionError as e:
+            if "Require 20 byte binary sha, got" in str(e):
+                return -1
+            else:
+                raise e
+
+        _ = blob.mime_type
+
+
+def main():
+    atheris.Setup(sys.argv, TestOneInput)
+    atheris.Fuzz()
+
+
+if __name__ == "__main__":
+    main()