Update to zlib 1.3.2 (#852)

1 files changed, 668 insertions, 594 deletions

diff --git a/Minecraft.Client/Common/zlib/gzread.c b/Minecraft.Client/Common/zlib/gzread.c
index bf4538eb..420a8065 100644
--- a/Minecraft.Client/Common/zlib/gzread.c
+++ b/Minecraft.Client/Common/zlib/gzread.c
@@ -1,594 +1,668 @@
-/* gzread.c -- zlib functions for reading gzip files
- * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
-
-#include "gzguts.h"
-
-/* Local functions */
-local int gz_load OF((gz_statep, unsigned char *, unsigned, unsigned *));
-local int gz_avail OF((gz_statep));
-local int gz_look OF((gz_statep));
-local int gz_decomp OF((gz_statep));
-local int gz_fetch OF((gz_statep));
-local int gz_skip OF((gz_statep, z_off64_t));
-
-/* Use read() to load a buffer -- return -1 on error, otherwise 0.  Read from
-   state->fd, and update state->eof, state->err, and state->msg as appropriate.
-   This function needs to loop on read(), since read() is not guaranteed to
-   read the number of bytes requested, depending on the type of descriptor. */
-local int gz_load(state, buf, len, have)
-    gz_statep state;
-    unsigned char *buf;
-    unsigned len;
-    unsigned *have;
-{
-    int ret;
-
-    *have = 0;
-    do {
-        ret = read(state->fd, buf + *have, len - *have);
-        if (ret <= 0)
-            break;
-        *have += ret;
-    } while (*have < len);
-    if (ret < 0) {
-        gz_error(state, Z_ERRNO, zstrerror());
-        return -1;
-    }
-    if (ret == 0)
-        state->eof = 1;
-    return 0;
-}
-
-/* Load up input buffer and set eof flag if last data loaded -- return -1 on
-   error, 0 otherwise.  Note that the eof flag is set when the end of the input
-   file is reached, even though there may be unused data in the buffer.  Once
-   that data has been used, no more attempts will be made to read the file.
-   If strm->avail_in != 0, then the current data is moved to the beginning of
-   the input buffer, and then the remainder of the buffer is loaded with the
-   available data from the input file. */
-local int gz_avail(state)
-    gz_statep state;
-{
-    unsigned got;
-    z_streamp strm = &(state->strm);
-
-    if (state->err != Z_OK && state->err != Z_BUF_ERROR)
-        return -1;
-    if (state->eof == 0) {
-        if (strm->avail_in) {       /* copy what's there to the start */
-            unsigned char *p = state->in;
-            unsigned const char *q = strm->next_in;
-            unsigned n = strm->avail_in;
-            do {
-                *p++ = *q++;
-            } while (--n);
-        }
-        if (gz_load(state, state->in + strm->avail_in,
-                    state->size - strm->avail_in, &got) == -1)
-            return -1;
-        strm->avail_in += got;
-        strm->next_in = state->in;
-    }
-    return 0;
-}
-
-/* Look for gzip header, set up for inflate or copy.  state->x.have must be 0.
-   If this is the first time in, allocate required memory.  state->how will be
-   left unchanged if there is no more input data available, will be set to COPY
-   if there is no gzip header and direct copying will be performed, or it will
-   be set to GZIP for decompression.  If direct copying, then leftover input
-   data from the input buffer will be copied to the output buffer.  In that
-   case, all further file reads will be directly to either the output buffer or
-   a user buffer.  If decompressing, the inflate state will be initialized.
-   gz_look() will return 0 on success or -1 on failure. */
-local int gz_look(state)
-    gz_statep state;
-{
-    z_streamp strm = &(state->strm);
-
-    /* allocate read buffers and inflate memory */
-    if (state->size == 0) {
-        /* allocate buffers */
-        state->in = (unsigned char *)malloc(state->want);
-        state->out = (unsigned char *)malloc(state->want << 1);
-        if (state->in == NULL || state->out == NULL) {
-            if (state->out != NULL)
-                free(state->out);
-            if (state->in != NULL)
-                free(state->in);
-            gz_error(state, Z_MEM_ERROR, "out of memory");
-            return -1;
-        }
-        state->size = state->want;
-
-        /* allocate inflate memory */
-        state->strm.zalloc = Z_NULL;
-        state->strm.zfree = Z_NULL;
-        state->strm.opaque = Z_NULL;
-        state->strm.avail_in = 0;
-        state->strm.next_in = Z_NULL;
-        if (inflateInit2(&(state->strm), 15 + 16) != Z_OK) {    /* gunzip */
-            free(state->out);
-            free(state->in);
-            state->size = 0;
-            gz_error(state, Z_MEM_ERROR, "out of memory");
-            return -1;
-        }
-    }
-
-    /* get at least the magic bytes in the input buffer */
-    if (strm->avail_in < 2) {
-        if (gz_avail(state) == -1)
-            return -1;
-        if (strm->avail_in == 0)
-            return 0;
-    }
-
-    /* look for gzip magic bytes -- if there, do gzip decoding (note: there is
-       a logical dilemma here when considering the case of a partially written
-       gzip file, to wit, if a single 31 byte is written, then we cannot tell
-       whether this is a single-byte file, or just a partially written gzip
-       file -- for here we assume that if a gzip file is being written, then
-       the header will be written in a single operation, so that reading a
-       single byte is sufficient indication that it is not a gzip file) */
-    if (strm->avail_in > 1 &&
-            strm->next_in[0] == 31 && strm->next_in[1] == 139) {
-        inflateReset(strm);
-        state->how = GZIP;
-        state->direct = 0;
-        return 0;
-    }
-
-    /* no gzip header -- if we were decoding gzip before, then this is trailing
-       garbage.  Ignore the trailing garbage and finish. */
-    if (state->direct == 0) {
-        strm->avail_in = 0;
-        state->eof = 1;
-        state->x.have = 0;
-        return 0;
-    }
-
-    /* doing raw i/o, copy any leftover input to output -- this assumes that
-       the output buffer is larger than the input buffer, which also assures
-       space for gzungetc() */
-    state->x.next = state->out;
-    if (strm->avail_in) {
-        memcpy(state->x.next, strm->next_in, strm->avail_in);
-        state->x.have = strm->avail_in;
-        strm->avail_in = 0;
-    }
-    state->how = COPY;
-    state->direct = 1;
-    return 0;
-}
-
-/* Decompress from input to the provided next_out and avail_out in the state.
-   On return, state->x.have and state->x.next point to the just decompressed
-   data.  If the gzip stream completes, state->how is reset to LOOK to look for
-   the next gzip stream or raw data, once state->x.have is depleted.  Returns 0
-   on success, -1 on failure. */
-local int gz_decomp(state)
-    gz_statep state;
-{
-    int ret = Z_OK;
-    unsigned had;
-    z_streamp strm = &(state->strm);
-
-    /* fill output buffer up to end of deflate stream */
-    had = strm->avail_out;
-    do {
-        /* get more input for inflate() */
-        if (strm->avail_in == 0 && gz_avail(state) == -1)
-            return -1;
-        if (strm->avail_in == 0) {
-            gz_error(state, Z_BUF_ERROR, "unexpected end of file");
-            break;
-        }
-
-        /* decompress and handle errors */
-        ret = inflate(strm, Z_NO_FLUSH);
-        if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
-            gz_error(state, Z_STREAM_ERROR,
-                     "internal error: inflate stream corrupt");
-            return -1;
-        }
-        if (ret == Z_MEM_ERROR) {
-            gz_error(state, Z_MEM_ERROR, "out of memory");
-            return -1;
-        }
-        if (ret == Z_DATA_ERROR) {              /* deflate stream invalid */
-            gz_error(state, Z_DATA_ERROR,
-                     strm->msg == NULL ? "compressed data error" : strm->msg);
-            return -1;
-        }
-    } while (strm->avail_out && ret != Z_STREAM_END);
-
-    /* update available output */
-    state->x.have = had - strm->avail_out;
-    state->x.next = strm->next_out - state->x.have;
-
-    /* if the gzip stream completed successfully, look for another */
-    if (ret == Z_STREAM_END)
-        state->how = LOOK;
-
-    /* good decompression */
-    return 0;
-}
-
-/* Fetch data and put it in the output buffer.  Assumes state->x.have is 0.
-   Data is either copied from the input file or decompressed from the input
-   file depending on state->how.  If state->how is LOOK, then a gzip header is
-   looked for to determine whether to copy or decompress.  Returns -1 on error,
-   otherwise 0.  gz_fetch() will leave state->how as COPY or GZIP unless the
-   end of the input file has been reached and all data has been processed.  */
-local int gz_fetch(state)
-    gz_statep state;
-{
-    z_streamp strm = &(state->strm);
-
-    do {
-        switch(state->how) {
-        case LOOK:      /* -> LOOK, COPY (only if never GZIP), or GZIP */
-            if (gz_look(state) == -1)
-                return -1;
-            if (state->how == LOOK)
-                return 0;
-            break;
-        case COPY:      /* -> COPY */
-            if (gz_load(state, state->out, state->size << 1, &(state->x.have))
-                    == -1)
-                return -1;
-            state->x.next = state->out;
-            return 0;
-        case GZIP:      /* -> GZIP or LOOK (if end of gzip stream) */
-            strm->avail_out = state->size << 1;
-            strm->next_out = state->out;
-            if (gz_decomp(state) == -1)
-                return -1;
-        }
-    } while (state->x.have == 0 && (!state->eof || strm->avail_in));
-    return 0;
-}
-
-/* Skip len uncompressed bytes of output.  Return -1 on error, 0 on success. */
-local int gz_skip(state, len)
-    gz_statep state;
-    z_off64_t len;
-{
-    unsigned n;
-
-    /* skip over len bytes or reach end-of-file, whichever comes first */
-    while (len)
-        /* skip over whatever is in output buffer */
-        if (state->x.have) {
-            n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > len ?
-                (unsigned)len : state->x.have;
-            state->x.have -= n;
-            state->x.next += n;
-            state->x.pos += n;
-            len -= n;
-        }
-
-        /* output buffer empty -- return if we're at the end of the input */
-        else if (state->eof && state->strm.avail_in == 0)
-            break;
-
-        /* need more data to skip -- load up output buffer */
-        else {
-            /* get more output, looking for header if required */
-            if (gz_fetch(state) == -1)
-                return -1;
-        }
-    return 0;
-}
-
-/* -- see zlib.h -- */
-int ZEXPORT gzread(file, buf, len)
-    gzFile file;
-    voidp buf;
-    unsigned len;
-{
-    unsigned got, n;
-    gz_statep state;
-    z_streamp strm;
-
-    /* get internal structure */
-    if (file == NULL)
-        return -1;
-    state = (gz_statep)file;
-    strm = &(state->strm);
-
-    /* check that we're reading and that there's no (serious) error */
-    if (state->mode != GZ_READ ||
-            (state->err != Z_OK && state->err != Z_BUF_ERROR))
-        return -1;
-
-    /* since an int is returned, make sure len fits in one, otherwise return
-       with an error (this avoids the flaw in the interface) */
-    if ((int)len < 0) {
-        gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
-        return -1;
-    }
-
-    /* if len is zero, avoid unnecessary operations */
-    if (len == 0)
-        return 0;
-
-    /* process a skip request */
-    if (state->seek) {
-        state->seek = 0;
-        if (gz_skip(state, state->skip) == -1)
-            return -1;
-    }
-
-    /* get len bytes to buf, or less than len if at the end */
-    got = 0;
-    do {
-        /* first just try copying data from the output buffer */
-        if (state->x.have) {
-            n = state->x.have > len ? len : state->x.have;
-            memcpy(buf, state->x.next, n);
-            state->x.next += n;
-            state->x.have -= n;
-        }
-
-        /* output buffer empty -- return if we're at the end of the input */
-        else if (state->eof && strm->avail_in == 0) {
-            state->past = 1;        /* tried to read past end */
-            break;
-        }
-
-        /* need output data -- for small len or new stream load up our output
-           buffer */
-        else if (state->how == LOOK || len < (state->size << 1)) {
-            /* get more output, looking for header if required */
-            if (gz_fetch(state) == -1)
-                return -1;
-            continue;       /* no progress yet -- go back to copy above */
-            /* the copy above assures that we will leave with space in the
-               output buffer, allowing at least one gzungetc() to succeed */
-        }
-
-        /* large len -- read directly into user buffer */
-        else if (state->how == COPY) {      /* read directly */
-            if (gz_load(state, (unsigned char *)buf, len, &n) == -1)
-                return -1;
-        }
-
-        /* large len -- decompress directly into user buffer */
-        else {  /* state->how == GZIP */
-            strm->avail_out = len;
-            strm->next_out = (unsigned char *)buf;
-            if (gz_decomp(state) == -1)
-                return -1;
-            n = state->x.have;
-            state->x.have = 0;
-        }
-
-        /* update progress */
-        len -= n;
-        buf = (char *)buf + n;
-        got += n;
-        state->x.pos += n;
-    } while (len);
-
-    /* return number of bytes read into user buffer (will fit in int) */
-    return (int)got;
-}
-
-/* -- see zlib.h -- */
-#ifdef Z_PREFIX_SET
-#  undef z_gzgetc
-#else
-#  undef gzgetc
-#endif
-int ZEXPORT gzgetc(file)
-    gzFile file;
-{
-    int ret;
-    unsigned char buf[1];
-    gz_statep state;
-
-    /* get internal structure */
-    if (file == NULL)
-        return -1;
-    state = (gz_statep)file;
-
-    /* check that we're reading and that there's no (serious) error */
-    if (state->mode != GZ_READ ||
-        (state->err != Z_OK && state->err != Z_BUF_ERROR))
-        return -1;
-
-    /* try output buffer (no need to check for skip request) */
-    if (state->x.have) {
-        state->x.have--;
-        state->x.pos++;
-        return *(state->x.next)++;
-    }
-
-    /* nothing there -- try gzread() */
-    ret = gzread(file, buf, 1);
-    return ret < 1 ? -1 : buf[0];
-}
-
-int ZEXPORT gzgetc_(file)
-gzFile file;
-{
-    return gzgetc(file);
-}
-
-/* -- see zlib.h -- */
-int ZEXPORT gzungetc(c, file)
-    int c;
-    gzFile file;
-{
-    gz_statep state;
-
-    /* get internal structure */
-    if (file == NULL)
-        return -1;
-    state = (gz_statep)file;
-
-    /* check that we're reading and that there's no (serious) error */
-    if (state->mode != GZ_READ ||
-        (state->err != Z_OK && state->err != Z_BUF_ERROR))
-        return -1;
-
-    /* process a skip request */
-    if (state->seek) {
-        state->seek = 0;
-        if (gz_skip(state, state->skip) == -1)
-            return -1;
-    }
-
-    /* can't push EOF */
-    if (c < 0)
-        return -1;
-
-    /* if output buffer empty, put byte at end (allows more pushing) */
-    if (state->x.have == 0) {
-        state->x.have = 1;
-        state->x.next = state->out + (state->size << 1) - 1;
-        state->x.next[0] = c;
-        state->x.pos--;
-        state->past = 0;
-        return c;
-    }
-
-    /* if no room, give up (must have already done a gzungetc()) */
-    if (state->x.have == (state->size << 1)) {
-        gz_error(state, Z_DATA_ERROR, "out of room to push characters");
-        return -1;
-    }
-
-    /* slide output data if needed and insert byte before existing data */
-    if (state->x.next == state->out) {
-        unsigned char *src = state->out + state->x.have;
-        unsigned char *dest = state->out + (state->size << 1);
-        while (src > state->out)
-            *--dest = *--src;
-        state->x.next = dest;
-    }
-    state->x.have++;
-    state->x.next--;
-    state->x.next[0] = c;
-    state->x.pos--;
-    state->past = 0;
-    return c;
-}
-
-/* -- see zlib.h -- */
-char * ZEXPORT gzgets(file, buf, len)
-    gzFile file;
-    char *buf;
-    int len;
-{
-    unsigned left, n;
-    char *str;
-    unsigned char *eol;
-    gz_statep state;
-
-    /* check parameters and get internal structure */
-    if (file == NULL || buf == NULL || len < 1)
-        return NULL;
-    state = (gz_statep)file;
-
-    /* check that we're reading and that there's no (serious) error */
-    if (state->mode != GZ_READ ||
-        (state->err != Z_OK && state->err != Z_BUF_ERROR))
-        return NULL;
-
-    /* process a skip request */
-    if (state->seek) {
-        state->seek = 0;
-        if (gz_skip(state, state->skip) == -1)
-            return NULL;
-    }
-
-    /* copy output bytes up to new line or len - 1, whichever comes first --
-       append a terminating zero to the string (we don't check for a zero in
-       the contents, let the user worry about that) */
-    str = buf;
-    left = (unsigned)len - 1;
-    if (left) do {
-        /* assure that something is in the output buffer */
-        if (state->x.have == 0 && gz_fetch(state) == -1)
-            return NULL;                /* error */
-        if (state->x.have == 0) {       /* end of file */
-            state->past = 1;            /* read past end */
-            break;                      /* return what we have */
-        }
-
-        /* look for end-of-line in current output buffer */
-        n = state->x.have > left ? left : state->x.have;
-        eol = (unsigned char *)memchr(state->x.next, '\n', n);
-        if (eol != NULL)
-            n = (unsigned)(eol - state->x.next) + 1;
-
-        /* copy through end-of-line, or remainder if not found */
-        memcpy(buf, state->x.next, n);
-        state->x.have -= n;
-        state->x.next += n;
-        state->x.pos += n;
-        left -= n;
-        buf += n;
-    } while (left && eol == NULL);
-
-    /* return terminated string, or if nothing, end of file */
-    if (buf == str)
-        return NULL;
-    buf[0] = 0;
-    return str;
-}
-
-/* -- see zlib.h -- */
-int ZEXPORT gzdirect(file)
-    gzFile file;
-{
-    gz_statep state;
-
-    /* get internal structure */
-    if (file == NULL)
-        return 0;
-    state = (gz_statep)file;
-
-    /* if the state is not known, but we can find out, then do so (this is
-       mainly for right after a gzopen() or gzdopen()) */
-    if (state->mode == GZ_READ && state->how == LOOK && state->x.have == 0)
-        (void)gz_look(state);
-
-    /* return 1 if transparent, 0 if processing a gzip stream */
-    return state->direct;
-}
-
-/* -- see zlib.h -- */
-int ZEXPORT gzclose_r(file)
-    gzFile file;
-{
-    int ret, err;
-    gz_statep state;
-
-    /* get internal structure */
-    if (file == NULL)
-        return Z_STREAM_ERROR;
-    state = (gz_statep)file;
-
-    /* check that we're reading */
-    if (state->mode != GZ_READ)
-        return Z_STREAM_ERROR;
-
-    /* free memory and close file */
-    if (state->size) {
-        inflateEnd(&(state->strm));
-        free(state->out);
-        free(state->in);
-    }
-    err = state->err == Z_BUF_ERROR ? Z_BUF_ERROR : Z_OK;
-    gz_error(state, Z_OK, NULL);
-    free(state->path);
-    ret = close(state->fd);
-    free(state);
-    return ret ? Z_ERRNO : err;
-}
+/* gzread.c -- zlib functions for reading gzip files

+ * Copyright (C) 2004-2026 Mark Adler

+ * For conditions of distribution and use, see copyright notice in zlib.h

+ */

+

+#include "gzguts.h"

+

+/* Use read() to load a buffer -- return -1 on error, otherwise 0.  Read from

+   state->fd, and update state->eof, state->err, and state->msg as appropriate.

+   This function needs to loop on read(), since read() is not guaranteed to

+   read the number of bytes requested, depending on the type of descriptor. It

+   also needs to loop to manage the fact that read() returns an int. If the

+   descriptor is non-blocking and read() returns with no data in order to avoid

+   blocking, then gz_load() will return 0 if some data has been read, or -1 if

+   no data has been read. Either way, state->again is set true to indicate a

+   non-blocking event. If errno is non-zero on return, then there was an error

+   signaled from read().  *have is set to the number of bytes read. */

+local int gz_load(gz_statep state, unsigned char *buf, unsigned len,

+                  unsigned *have) {

+    int ret;

+    unsigned get, max = ((unsigned)-1 >> 2) + 1;

+

+    state->again = 0;

+    errno = 0;

+    *have = 0;

+    do {

+        get = len - *have;

+        if (get > max)

+            get = max;

+        ret = (int)read(state->fd, buf + *have, get);

+        if (ret <= 0)

+            break;

+        *have += (unsigned)ret;

+    } while (*have < len);

+    if (ret < 0) {

+        if (errno == EAGAIN || errno == EWOULDBLOCK) {

+            state->again = 1;

+            if (*have != 0)

+                return 0;

+        }

+        gz_error(state, Z_ERRNO, zstrerror());

+        return -1;

+    }

+    if (ret == 0)

+        state->eof = 1;

+    return 0;

+}

+

+/* Load up input buffer and set eof flag if last data loaded -- return -1 on

+   error, 0 otherwise.  Note that the eof flag is set when the end of the input

+   file is reached, even though there may be unused data in the buffer.  Once

+   that data has been used, no more attempts will be made to read the file.

+   If strm->avail_in != 0, then the current data is moved to the beginning of

+   the input buffer, and then the remainder of the buffer is loaded with the

+   available data from the input file. */

+local int gz_avail(gz_statep state) {

+    unsigned got;

+    z_streamp strm = &(state->strm);

+

+    if (state->err != Z_OK && state->err != Z_BUF_ERROR)

+        return -1;

+    if (state->eof == 0) {

+        if (strm->avail_in) {       /* copy what's there to the start */

+            unsigned char *p = state->in;

+            unsigned const char *q = strm->next_in;

+

+            if (q != p) {

+                unsigned n = strm->avail_in;

+

+                do {

+                    *p++ = *q++;

+                } while (--n);

+            }

+        }

+        if (gz_load(state, state->in + strm->avail_in,

+                    state->size - strm->avail_in, &got) == -1)

+            return -1;

+        strm->avail_in += got;

+        strm->next_in = state->in;

+    }

+    return 0;

+}

+

+/* Look for gzip header, set up for inflate or copy.  state->x.have must be 0.

+   If this is the first time in, allocate required memory.  state->how will be

+   left unchanged if there is no more input data available, will be set to COPY

+   if there is no gzip header and direct copying will be performed, or it will

+   be set to GZIP for decompression.  If direct copying, then leftover input

+   data from the input buffer will be copied to the output buffer.  In that

+   case, all further file reads will be directly to either the output buffer or

+   a user buffer.  If decompressing, the inflate state will be initialized.

+   gz_look() will return 0 on success or -1 on failure. */

+local int gz_look(gz_statep state) {

+    z_streamp strm = &(state->strm);

+

+    /* allocate read buffers and inflate memory */

+    if (state->size == 0) {

+        /* allocate buffers */

+        state->in = (unsigned char *)malloc(state->want);

+        state->out = (unsigned char *)malloc(state->want << 1);

+        if (state->in == NULL || state->out == NULL) {

+            free(state->out);

+            free(state->in);

+            gz_error(state, Z_MEM_ERROR, "out of memory");

+            return -1;

+        }

+        state->size = state->want;

+

+        /* allocate inflate memory */

+        state->strm.zalloc = Z_NULL;

+        state->strm.zfree = Z_NULL;

+        state->strm.opaque = Z_NULL;

+        state->strm.avail_in = 0;

+        state->strm.next_in = Z_NULL;

+        if (inflateInit2(&(state->strm), 15 + 16) != Z_OK) {    /* gunzip */

+            free(state->out);

+            free(state->in);

+            state->size = 0;

+            gz_error(state, Z_MEM_ERROR, "out of memory");

+            return -1;

+        }

+    }

+

+    /* if transparent reading is disabled, which would only be at the start, or

+       if we're looking for a gzip member after the first one, which is not at

+       the start, then proceed directly to look for a gzip member next */

+    if (state->direct == -1 || state->junk == 0) {

+        inflateReset(strm);

+        state->how = GZIP;

+        state->junk = state->junk != -1;

+        state->direct = 0;

+        return 0;

+    }

+

+    /* otherwise we're at the start with auto-detect -- we check to see if the

+       first four bytes could be gzip header in order to decide whether or not

+       this will be a transparent read */

+

+    /* load any header bytes into the input buffer -- if the input is empty,

+       then it's not an error as this is a transparent read of zero bytes */

+    if (gz_avail(state) == -1)

+        return -1;

+    if (strm->avail_in == 0 || (state->again && strm->avail_in < 4))

+        /* if non-blocking input stalled before getting four bytes, then

+           return and wait until a later call has accumulated enough */

+        return 0;

+

+    /* see if this is (likely) gzip input -- if the first four bytes are

+       consistent with a gzip header, then go look for the first gzip member,

+       otherwise proceed to copy the input transparently */

+    if (strm->avail_in > 3 &&

+            strm->next_in[0] == 31 && strm->next_in[1] == 139 &&

+            strm->next_in[2] == 8 && strm->next_in[3] < 32) {

+        inflateReset(strm);

+        state->how = GZIP;

+        state->junk = 1;

+        state->direct = 0;

+        return 0;

+    }

+

+    /* doing raw i/o: copy any leftover input to output -- this assumes that

+       the output buffer is larger than the input buffer, which also assures

+       space for gzungetc() */

+    state->x.next = state->out;

+    memcpy(state->x.next, strm->next_in, strm->avail_in);

+    state->x.have = strm->avail_in;

+    strm->avail_in = 0;

+    state->how = COPY;

+    return 0;

+}

+

+/* Decompress from input to the provided next_out and avail_out in the state.

+   On return, state->x.have and state->x.next point to the just decompressed

+   data. If the gzip stream completes, state->how is reset to LOOK to look for

+   the next gzip stream or raw data, once state->x.have is depleted. Returns 0

+   on success, -1 on failure. If EOF is reached when looking for more input to

+   complete the gzip member, then an unexpected end of file error is raised.

+   If there is no more input, but state->again is true, then EOF has not been

+   reached, and no error is raised. */

+local int gz_decomp(gz_statep state) {

+    int ret = Z_OK;

+    unsigned had;

+    z_streamp strm = &(state->strm);

+

+    /* fill output buffer up to end of deflate stream */

+    had = strm->avail_out;

+    do {

+        /* get more input for inflate() */

+        if (strm->avail_in == 0 && gz_avail(state) == -1) {

+            ret = state->err;

+            break;

+        }

+        if (strm->avail_in == 0) {

+            if (!state->again)

+                gz_error(state, Z_BUF_ERROR, "unexpected end of file");

+            break;

+        }

+

+        /* decompress and handle errors */

+        ret = inflate(strm, Z_NO_FLUSH);

+        if (strm->avail_out < had)

+            /* any decompressed data marks this as a real gzip stream */

+            state->junk = 0;

+        if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {

+            gz_error(state, Z_STREAM_ERROR,

+                     "internal error: inflate stream corrupt");

+            break;

+        }

+        if (ret == Z_MEM_ERROR) {

+            gz_error(state, Z_MEM_ERROR, "out of memory");

+            break;

+        }

+        if (ret == Z_DATA_ERROR) {              /* deflate stream invalid */

+            if (state->junk == 1) {             /* trailing garbage is ok */

+                strm->avail_in = 0;

+                state->eof = 1;

+                state->how = LOOK;

+                ret = Z_OK;

+                break;

+            }

+            gz_error(state, Z_DATA_ERROR,

+                     strm->msg == NULL ? "compressed data error" : strm->msg);

+            break;

+        }

+    } while (strm->avail_out && ret != Z_STREAM_END);

+

+    /* update available output */

+    state->x.have = had - strm->avail_out;

+    state->x.next = strm->next_out - state->x.have;

+

+    /* if the gzip stream completed successfully, look for another */

+    if (ret == Z_STREAM_END) {

+        state->junk = 0;

+        state->how = LOOK;

+        return 0;

+    }

+

+    /* return decompression status */

+    return ret != Z_OK ? -1 : 0;

+}

+

+/* Fetch data and put it in the output buffer.  Assumes state->x.have is 0.

+   Data is either copied from the input file or decompressed from the input

+   file depending on state->how.  If state->how is LOOK, then a gzip header is

+   looked for to determine whether to copy or decompress.  Returns -1 on error,

+   otherwise 0.  gz_fetch() will leave state->how as COPY or GZIP unless the

+   end of the input file has been reached and all data has been processed.  */

+local int gz_fetch(gz_statep state) {

+    z_streamp strm = &(state->strm);

+

+    do {

+        switch(state->how) {

+        case LOOK:      /* -> LOOK, COPY (only if never GZIP), or GZIP */

+            if (gz_look(state) == -1)

+                return -1;

+            if (state->how == LOOK)

+                return 0;

+            break;

+        case COPY:      /* -> COPY */

+            if (gz_load(state, state->out, state->size << 1, &(state->x.have))

+                    == -1)

+                return -1;

+            state->x.next = state->out;

+            return 0;

+        case GZIP:      /* -> GZIP or LOOK (if end of gzip stream) */

+            strm->avail_out = state->size << 1;

+            strm->next_out = state->out;

+            if (gz_decomp(state) == -1)

+                return -1;

+            break;

+        default:

+            gz_error(state, Z_STREAM_ERROR, "state corrupt");

+            return -1;

+        }

+    } while (state->x.have == 0 && (!state->eof || strm->avail_in));

+    return 0;

+}

+

+/* Skip state->skip (> 0) uncompressed bytes of output.  Return -1 on error, 0

+   on success. */

+local int gz_skip(gz_statep state) {

+    unsigned n;

+

+    /* skip over len bytes or reach end-of-file, whichever comes first */

+    do {

+        /* skip over whatever is in output buffer */

+        if (state->x.have) {

+            n = GT_OFF(state->x.have) ||

+                (z_off64_t)state->x.have > state->skip ?

+                (unsigned)state->skip : state->x.have;

+            state->x.have -= n;

+            state->x.next += n;

+            state->x.pos += n;

+            state->skip -= n;

+        }

+

+        /* output buffer empty -- return if we're at the end of the input */

+        else if (state->eof && state->strm.avail_in == 0)

+            break;

+

+        /* need more data to skip -- load up output buffer */

+        else {

+            /* get more output, looking for header if required */

+            if (gz_fetch(state) == -1)

+                return -1;

+        }

+    } while (state->skip);

+    return 0;

+}

+

+/* Read len bytes into buf from file, or less than len up to the end of the

+   input. Return the number of bytes read. If zero is returned, either the end

+   of file was reached, or there was an error. state->err must be consulted in

+   that case to determine which. If there was an error, but some uncompressed

+   bytes were read before the error, then that count is returned. The error is

+   still recorded, and so is deferred until the next call. */

+local z_size_t gz_read(gz_statep state, voidp buf, z_size_t len) {

+    z_size_t got;

+    unsigned n;

+    int err;

+

+    /* if len is zero, avoid unnecessary operations */

+    if (len == 0)

+        return 0;

+

+    /* process a skip request */

+    if (state->skip && gz_skip(state) == -1)

+        return 0;

+

+    /* get len bytes to buf, or less than len if at the end */

+    got = 0;

+    err = 0;

+    do {

+        /* set n to the maximum amount of len that fits in an unsigned int */

+        n = (unsigned)-1;

+        if (n > len)

+            n = (unsigned)len;

+

+        /* first just try copying data from the output buffer */

+        if (state->x.have) {

+            if (state->x.have < n)

+                n = state->x.have;

+            memcpy(buf, state->x.next, n);

+            state->x.next += n;

+            state->x.have -= n;

+            if (state->err != Z_OK)

+                /* caught deferred error from gz_fetch() */

+                err = -1;

+        }

+

+        /* output buffer empty -- return if we're at the end of the input */

+        else if (state->eof && state->strm.avail_in == 0)

+            break;

+

+        /* need output data -- for small len or new stream load up our output

+           buffer, so that gzgetc() can be fast */

+        else if (state->how == LOOK || n < (state->size << 1)) {

+            /* get more output, looking for header if required */

+            if (gz_fetch(state) == -1 && state->x.have == 0)

+                /* if state->x.have != 0, error will be caught after copy */

+                err = -1;

+            continue;       /* no progress yet -- go back to copy above */

+            /* the copy above assures that we will leave with space in the

+               output buffer, allowing at least one gzungetc() to succeed */

+        }

+

+        /* large len -- read directly into user buffer */

+        else if (state->how == COPY)        /* read directly */

+            err = gz_load(state, (unsigned char *)buf, n, &n);

+

+        /* large len -- decompress directly into user buffer */

+        else {  /* state->how == GZIP */

+            state->strm.avail_out = n;

+            state->strm.next_out = (unsigned char *)buf;

+            err = gz_decomp(state);

+            n = state->x.have;

+            state->x.have = 0;

+        }

+

+        /* update progress */

+        len -= n;

+        buf = (char *)buf + n;

+        got += n;

+        state->x.pos += n;

+    } while (len && !err);

+

+    /* note read past eof */

+    if (len && state->eof)

+        state->past = 1;

+

+    /* return number of bytes read into user buffer */

+    return got;

+}

+

+/* -- see zlib.h -- */

+int ZEXPORT gzread(gzFile file, voidp buf, unsigned len) {

+    gz_statep state;

+

+    /* get internal structure and check that it's for reading */

+    if (file == NULL)

+        return -1;

+    state = (gz_statep)file;

+    if (state->mode != GZ_READ)

+        return -1;

+

+    /* check that there was no (serious) error */

+    if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)

+        return -1;

+    gz_error(state, Z_OK, NULL);

+

+    /* since an int is returned, make sure len fits in one, otherwise return

+       with an error (this avoids a flaw in the interface) */

+    if ((int)len < 0) {

+        gz_error(state, Z_STREAM_ERROR, "request does not fit in an int");

+        return -1;

+    }

+

+    /* read len or fewer bytes to buf */

+    len = (unsigned)gz_read(state, buf, len);

+

+    /* check for an error */

+    if (len == 0) {

+        if (state->err != Z_OK && state->err != Z_BUF_ERROR)

+            return -1;

+        if (state->again) {

+            /* non-blocking input stalled after some input was read, but no

+               uncompressed bytes were produced -- let the application know

+               this isn't EOF */

+            gz_error(state, Z_ERRNO, zstrerror());

+            return -1;

+        }

+    }

+

+    /* return the number of bytes read */

+    return (int)len;

+}

+

+/* -- see zlib.h -- */

+z_size_t ZEXPORT gzfread(voidp buf, z_size_t size, z_size_t nitems,

+                         gzFile file) {

+    z_size_t len;

+    gz_statep state;

+

+    /* get internal structure and check that it's for reading */

+    if (file == NULL)

+        return 0;

+    state = (gz_statep)file;

+    if (state->mode != GZ_READ)

+        return 0;

+

+    /* check that there was no (serious) error */

+    if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)

+        return 0;

+    gz_error(state, Z_OK, NULL);

+

+    /* compute bytes to read -- error on overflow */

+    len = nitems * size;

+    if (size && len / size != nitems) {

+        gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");

+        return 0;

+    }

+

+    /* read len or fewer bytes to buf, return the number of full items read */

+    return len ? gz_read(state, buf, len) / size : 0;

+}

+

+/* -- see zlib.h -- */

+#ifdef Z_PREFIX_SET

+#  undef z_gzgetc

+#else

+#  undef gzgetc

+#endif

+int ZEXPORT gzgetc(gzFile file) {

+    unsigned char buf[1];

+    gz_statep state;

+

+    /* get internal structure and check that it's for reading */

+    if (file == NULL)

+        return -1;

+    state = (gz_statep)file;

+    if (state->mode != GZ_READ)

+        return -1;

+

+    /* check that there was no (serious) error */

+    if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)

+        return -1;

+    gz_error(state, Z_OK, NULL);

+

+    /* try output buffer (no need to check for skip request) */

+    if (state->x.have) {

+        state->x.have--;

+        state->x.pos++;

+        return *(state->x.next)++;

+    }

+

+    /* nothing there -- try gz_read() */

+    return gz_read(state, buf, 1) < 1 ? -1 : buf[0];

+}

+

+int ZEXPORT gzgetc_(gzFile file) {

+    return gzgetc(file);

+}

+

+/* -- see zlib.h -- */

+int ZEXPORT gzungetc(int c, gzFile file) {

+    gz_statep state;

+

+    /* get internal structure and check that it's for reading */

+    if (file == NULL)

+        return -1;

+    state = (gz_statep)file;

+    if (state->mode != GZ_READ)

+        return -1;

+

+    /* in case this was just opened, set up the input buffer */

+    if (state->how == LOOK && state->x.have == 0)

+        (void)gz_look(state);

+

+    /* check that there was no (serious) error */

+    if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)

+        return -1;

+    gz_error(state, Z_OK, NULL);

+

+    /* process a skip request */

+    if (state->skip && gz_skip(state) == -1)

+        return -1;

+

+    /* can't push EOF */

+    if (c < 0)

+        return -1;

+

+    /* if output buffer empty, put byte at end (allows more pushing) */

+    if (state->x.have == 0) {

+        state->x.have = 1;

+        state->x.next = state->out + (state->size << 1) - 1;

+        state->x.next[0] = (unsigned char)c;

+        state->x.pos--;

+        state->past = 0;

+        return c;

+    }

+

+    /* if no room, give up (must have already done a gzungetc()) */

+    if (state->x.have == (state->size << 1)) {

+        gz_error(state, Z_DATA_ERROR, "out of room to push characters");

+        return -1;

+    }

+

+    /* slide output data if needed and insert byte before existing data */

+    if (state->x.next == state->out) {

+        unsigned char *src = state->out + state->x.have;

+        unsigned char *dest = state->out + (state->size << 1);

+

+        while (src > state->out)

+            *--dest = *--src;

+        state->x.next = dest;

+    }

+    state->x.have++;

+    state->x.next--;

+    state->x.next[0] = (unsigned char)c;

+    state->x.pos--;

+    state->past = 0;

+    return c;

+}

+

+/* -- see zlib.h -- */

+char * ZEXPORT gzgets(gzFile file, char *buf, int len) {

+    unsigned left, n;

+    char *str;

+    unsigned char *eol;

+    gz_statep state;

+

+    /* check parameters, get internal structure, and check that it's for

+       reading */

+    if (file == NULL || buf == NULL || len < 1)

+        return NULL;

+    state = (gz_statep)file;

+    if (state->mode != GZ_READ)

+        return NULL;

+

+    /* check that there was no (serious) error */

+    if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)

+        return NULL;

+    gz_error(state, Z_OK, NULL);

+

+    /* process a skip request */

+    if (state->skip && gz_skip(state) == -1)

+        return NULL;

+

+    /* copy output up to a new line, len-1 bytes, or there is no more output,

+       whichever comes first */

+    str = buf;

+    left = (unsigned)len - 1;

+    if (left) do {

+        /* assure that something is in the output buffer */

+        if (state->x.have == 0 && gz_fetch(state) == -1)

+            break;                      /* error */

+        if (state->x.have == 0) {       /* end of file */

+            state->past = 1;            /* read past end */

+            break;                      /* return what we have */

+        }

+

+        /* look for end-of-line in current output buffer */

+        n = state->x.have > left ? left : state->x.have;

+        eol = (unsigned char *)memchr(state->x.next, '\n', n);

+        if (eol != NULL)

+            n = (unsigned)(eol - state->x.next) + 1;

+

+        /* copy through end-of-line, or remainder if not found */

+        memcpy(buf, state->x.next, n);

+        state->x.have -= n;

+        state->x.next += n;

+        state->x.pos += n;

+        left -= n;

+        buf += n;

+    } while (left && eol == NULL);

+

+    /* append a terminating zero to the string (we don't check for a zero in

+       the contents, let the user worry about that) -- return the terminated

+       string, or if nothing was read, NULL */

+    if (buf == str)

+        return NULL;

+    buf[0] = 0;

+    return str;

+}

+

+/* -- see zlib.h -- */

+int ZEXPORT gzdirect(gzFile file) {

+    gz_statep state;

+

+    /* get internal structure */

+    if (file == NULL)

+        return 0;

+    state = (gz_statep)file;

+

+    /* if the state is not known, but we can find out, then do so (this is

+       mainly for right after a gzopen() or gzdopen()) */

+    if (state->mode == GZ_READ && state->how == LOOK && state->x.have == 0)

+        (void)gz_look(state);

+

+    /* return 1 if transparent, 0 if processing a gzip stream */

+    return state->direct == 1;

+}

+

+/* -- see zlib.h -- */

+int ZEXPORT gzclose_r(gzFile file) {

+    int ret, err;

+    gz_statep state;

+

+    /* get internal structure and check that it's for reading */

+    if (file == NULL)

+        return Z_STREAM_ERROR;

+    state = (gz_statep)file;

+    if (state->mode != GZ_READ)

+        return Z_STREAM_ERROR;

+

+    /* free memory and close file */

+    if (state->size) {

+        inflateEnd(&(state->strm));

+        free(state->out);

+        free(state->in);

+    }

+    err = state->err == Z_BUF_ERROR ? Z_BUF_ERROR : Z_OK;

+    gz_error(state, Z_OK, NULL);

+    free(state->path);

+    ret = close(state->fd);

+    free(state);

+    return ret ? Z_ERRNO : err;

+}