diff --git a/contrib/infback9/inflate9.h b/contrib/infback9/inflate9.h
new file mode 100644
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+++ b/contrib/infback9/inflate9.h
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+/* inflate9.h -- internal inflate state definition
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Possible inflate modes between inflate() calls */
+typedef enum {
+        TYPE,       /* i: waiting for type bits, including last-flag bit */
+        STORED,     /* i: waiting for stored size (length and complement) */
+        TABLE,      /* i: waiting for dynamic block table lengths */
+            LEN,        /* i: waiting for length/lit code */
+    DONE,       /* finished check, done -- remain here until reset */
+    BAD         /* got a data error -- remain here until reset */
+} inflate_mode;
+
+/*
+    State transitions between above modes -
+
+    (most modes can go to the BAD mode -- not shown for clarity)
+
+    Read deflate blocks:
+            TYPE -> STORED or TABLE or LEN or DONE
+            STORED -> TYPE
+            TABLE -> LENLENS -> CODELENS -> LEN
+    Read deflate codes:
+                LEN -> LEN or TYPE
+ */
+
+/* state maintained between inflate() calls.  Approximately 7K bytes. */
+struct inflate_state {
+        /* sliding window */
+    unsigned char FAR *window;  /* allocated sliding window, if needed */
+        /* dynamic table building */
+    unsigned ncode;             /* number of code length code lengths */
+    unsigned nlen;              /* number of length code lengths */
+    unsigned ndist;             /* number of distance code lengths */
+    unsigned have;              /* number of code lengths in lens[] */
+    code FAR *next;             /* next available space in codes[] */
+    unsigned short lens[320];   /* temporary storage for code lengths */
+    unsigned short work[288];   /* work area for code table building */
+    code codes[ENOUGH];         /* space for code tables */
+};