gunzip: support concatenated gz files.

   text    data     bss     dec     hex filename
 770988    1029    9552  781569   bed01 busybox.t0/busybox
 771105    1029    9552  781686   bed76 busybox.t3/busybox

7 files changed, 368 insertions, 249 deletions

diff --git a/archival/bbunzip.c b/archival/bbunzip.c
index bccc8f898..e106bf0ed 100644
--- a/archival/bbunzip.c
+++ b/archival/bbunzip.c
@@ -74,7 +74,7 @@ int bbunpack(char **argv,
                                 goto err;
                         }
                         /* O_EXCL: "real" bunzip2 doesn't overwrite files */
-                        /* GNU gunzip goes not bail out, but goes to next file */
+                        /* GNU gunzip does not bail out, but goes to next file */
                         if (open_to_or_warn(STDOUT_FILENO, new_name, O_WRONLY | O_CREAT | O_EXCL,
                                         stat_buf.st_mode))
                                 goto err;
@@ -241,7 +241,6 @@ USE_DESKTOP(long long) int unpack_gunzip(void)
                 if (ENABLE_FEATURE_GUNZIP_UNCOMPRESS && magic2 == 0x9d) {
                         status = uncompress(STDIN_FILENO, STDOUT_FILENO);
                 } else if (magic2 == 0x8b) {
-                        check_header_gzip_or_die(STDIN_FILENO);
                         status = unpack_gz_stream(STDIN_FILENO, STDOUT_FILENO);
                 } else {
                         goto bad_magic;
diff --git a/archival/libunarchive/Kbuild b/archival/libunarchive/Kbuild
index d104524e4..a58a84f4b 100644
--- a/archival/libunarchive/Kbuild
+++ b/archival/libunarchive/Kbuild
@@ -28,7 +28,8 @@ lib-y:= \
         find_list_entry.o \
         init_handle.o
 
-GUNZIP_FILES:= check_header_gzip.o decompress_unzip.o
+GUNZIP_FILES:= decompress_unzip.o
+
 DPKG_FILES:= \
         get_header_ar.o \
         unpack_ar_archive.o \
diff --git a/archival/libunarchive/decompress_unzip.c b/archival/libunarchive/decompress_unzip.c
index 275f80b33..52be6b25d 100644
--- a/archival/libunarchive/decompress_unzip.c
+++ b/archival/libunarchive/decompress_unzip.c
@@ -33,21 +33,22 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
+#include <setjmp.h>
 #include "libbb.h"
 #include "unarchive.h"
 
-typedef struct huft_s {
+typedef struct huft_t {
         unsigned char e;        /* number of extra bits or operation */
         unsigned char b;        /* number of bits in this code or subcode */
         union {
                 unsigned short n;       /* literal, length base, or distance base */
-                struct huft_s *t;       /* pointer to next level of table */
+                struct huft_t *t;       /* pointer to next level of table */
         } v;
 } huft_t;
 
 enum {
         /* gunzip_window size--must be a power of two, and
-         *  at least 32K for zip's deflate method */
+         * at least 32K for zip's deflate method */
         GUNZIP_WSIZE = 0x8000,
         /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
         BMAX = 16,      /* maximum bit length of any code (16 for explode) */
@@ -82,11 +83,11 @@ typedef struct state_t {
         unsigned gunzip_bb; /* bit buffer */
         unsigned char gunzip_bk; /* bits in bit buffer */
 
-        /* These control the size of the STATE()bytebuffer */
-        unsigned bytebuffer_max;
-        unsigned char *bytebuffer;
-        unsigned bytebuffer_offset;
-        unsigned bytebuffer_size;
+        /* input (compressed) data */
+        unsigned char *bytebuffer;      /* buffer itself */
+        unsigned bytebuffer_max;        /* buffer size */
+        unsigned bytebuffer_offset;     /* buffer position */
+        unsigned bytebuffer_size;       /* how much data is there (size <= max) */
 
         /* private data of inflate_codes() */
         unsigned inflate_codes_ml; /* masks for bl and bd bits */
@@ -100,10 +101,11 @@ typedef struct state_t {
         unsigned inflate_codes_bd;
         unsigned inflate_codes_nn; /* length and index for copy */
         unsigned inflate_codes_dd;
+
         smallint resume_copy;
 
         /* private data of inflate_get_next_window() */
-        smallint method; /* Method == -1 for stored, -2 for codes */
+        smallint method; /* method == -1 for stored, -2 for codes */
         smallint need_another_block;
         smallint end_reached;
 
@@ -112,6 +114,9 @@ typedef struct state_t {
         unsigned inflate_stored_b;
         unsigned inflate_stored_k;
         unsigned inflate_stored_w;
+
+        const char *error_msg;
+        jmp_buf error_jmp;
 } state_t;
 #define gunzip_bytes_out    (S()gunzip_bytes_out   )
 #define gunzip_crc          (S()gunzip_crc         )
@@ -144,13 +149,13 @@ typedef struct state_t {
 #define inflate_stored_b    (S()inflate_stored_b   )
 #define inflate_stored_k    (S()inflate_stored_k   )
 #define inflate_stored_w    (S()inflate_stored_w   )
-#define INIT_STATE ({ bytebuffer_size = 0; method = -1; need_another_block = 1; })
+#define error_msg           (S()error_msg          )
+#define error_jmp           (S()error_jmp          )
 
-
-/* This is generic part */
+/* This is a generic part */
 #if STATE_IN_BSS /* Use global data segment */
 #define DECLARE_STATE /*nothing*/
-#define ALLOC_STATE (init_state())
+#define ALLOC_STATE /*nothing*/
 #define DEALLOC_STATE ((void)0)
 #define S() state.
 #define PASS_STATE /*nothing*/
@@ -158,86 +163,56 @@ typedef struct state_t {
 #define STATE_PARAM /*nothing*/
 #define STATE_PARAM_ONLY void
 static state_t state;
-static void init_state(void)
-{
-        INIT_STATE;
-}
 #endif
 
 #if STATE_IN_MALLOC /* Use malloc space */
 #define DECLARE_STATE state_t *state
-#define ALLOC_STATE (state = alloc_state())
+#define ALLOC_STATE (state = xzalloc(sizeof(*state)))
 #define DEALLOC_STATE free(state)
 #define S() state->
 #define PASS_STATE state,
 #define PASS_STATE_ONLY state
 #define STATE_PARAM state_t *state,
 #define STATE_PARAM_ONLY state_t *state
-static state_t* alloc_state(void)
-{
-        state_t* state = xzalloc(sizeof(*state));
-        INIT_STATE;
-        return state;
-}
 #endif
 
 
-static const unsigned short mask_bits[] ALIGN2 = {
+static const uint16_t mask_bits[] ALIGN2 = {
         0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
         0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
 };
 
 /* Copy lengths for literal codes 257..285 */
-static const unsigned short cplens[] ALIGN2 = {
+static const uint16_t cplens[] ALIGN2 = {
         3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
         67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
 };
 
 /* note: see note #13 above about the 258 in this list. */
 /* Extra bits for literal codes 257..285 */
-static const unsigned char cplext[] ALIGN1 = {
+static const uint8_t cplext[] ALIGN1 = {
         0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5,
         5, 5, 5, 0, 99, 99
 }; /* 99 == invalid */
 
 /* Copy offsets for distance codes 0..29 */
-static const unsigned short cpdist[] ALIGN2 = {
+static const uint16_t cpdist[] ALIGN2 = {
         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
         769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
 };
 
 /* Extra bits for distance codes */
-static const unsigned char cpdext[] ALIGN1 = {
+static const uint8_t cpdext[] ALIGN1 = {
         0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10,
         11, 11, 12, 12, 13, 13
 };
 
 /* Tables for deflate from PKZIP's appnote.txt. */
 /* Order of the bit length code lengths */
-static const unsigned char border[] ALIGN1 = {
+static const uint8_t border[] ALIGN1 = {
         16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
 };
 
-static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current, const unsigned required)
-{
-        while (*current < required) {
-                if (bytebuffer_offset >= bytebuffer_size) {
-                        /* Leave the first 4 bytes empty so we can always unwind the bitbuffer
-                         * to the front of the bytebuffer, leave 4 bytes free at end of tail
-                         * so we can easily top up buffer in check_trailer_gzip() */
-                        bytebuffer_size = safe_read(gunzip_src_fd, &bytebuffer[4], bytebuffer_max - 8);
-                        if (1 > bytebuffer_size)
-//shouldn't we propagate error?
-                                bb_error_msg_and_die("unexpected end of file");
-                        bytebuffer_size += 4;
-                        bytebuffer_offset = 4;
-                }
-                bitbuffer |= ((unsigned) bytebuffer[bytebuffer_offset]) << *current;
-                bytebuffer_offset++;
-                *current += 8;
-        }
-        return bitbuffer;
-}
 
 /*
  * Free the malloc'ed tables built by huft_build(), which makes a linked
@@ -245,7 +220,7 @@ static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current
  * each table.
  * t: table to free
  */
-static void huft_free(huft_t * p)
+static void huft_free(huft_t *p)
 {
         huft_t *q;
 
@@ -257,11 +232,48 @@ static void huft_free(huft_t * p)
         }
 }
 
+static void huft_free_all(STATE_PARAM_ONLY)
+{
+        huft_free(inflate_codes_tl);
+        huft_free(inflate_codes_td);
+        inflate_codes_tl = NULL;
+        inflate_codes_td = NULL;
+}
+
+static void abort_unzip(STATE_PARAM_ONLY) ATTRIBUTE_NORETURN;
+static void abort_unzip(STATE_PARAM_ONLY)
+{
+        huft_free_all(PASS_STATE_ONLY);
+        longjmp(error_jmp, 1);
+}
+
+static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current, const unsigned required)
+{
+        while (*current < required) {
+                if (bytebuffer_offset >= bytebuffer_size) {
+                        /* Leave the first 4 bytes empty so we can always unwind the bitbuffer
+                         * to the front of the bytebuffer */
+                        bytebuffer_size = safe_read(gunzip_src_fd, &bytebuffer[4], bytebuffer_max - 4);
+                        if ((int)bytebuffer_size < 1) {
+                                error_msg = "unexpected end of file";
+                                abort_unzip(PASS_STATE_ONLY);
+                        }
+                        bytebuffer_size += 4;
+                        bytebuffer_offset = 4;
+                }
+                bitbuffer |= ((unsigned) bytebuffer[bytebuffer_offset]) << *current;
+                bytebuffer_offset++;
+                *current += 8;
+        }
+        return bitbuffer;
+}
+
+
 /* Given a list of code lengths and a maximum table size, make a set of
  * tables to decode that set of codes.  Return zero on success, one if
  * the given code set is incomplete (the tables are still built in this
  * case), two if the input is invalid (all zero length codes or an
- * oversubscribed set of lengths), and three if not enough memory.
+ * oversubscribed set of lengths) - in this case stores NULL in *t.
  *
  * b:   code lengths in bits (all assumed <= BMAX)
  * n:   number of codes (assumed <= N_MAX)
@@ -271,66 +283,67 @@ static void huft_free(huft_t * p)
  * t:   result: starting table
  * m:   maximum lookup bits, returns actual
  */
-static int huft_build(unsigned *b, const unsigned n,
+static int huft_build(const unsigned *b, const unsigned n,
                            const unsigned s, const unsigned short *d,
-                           const unsigned char *e, huft_t ** t, unsigned *m)
+                           const unsigned char *e, huft_t **t, unsigned *m)
 {
-        unsigned a;                             /* counter for codes of length k */
-        unsigned c[BMAX + 1];   /* bit length count table */
-        unsigned eob_len;               /* length of end-of-block code (value 256) */
-        unsigned f;                             /* i repeats in table every f entries */
-        int g;                                  /* maximum code length */
-        int htl;                                /* table level */
-        unsigned i;                             /* counter, current code */
-        unsigned j;                             /* counter */
-        int k;                                  /* number of bits in current code */
-        unsigned *p;                    /* pointer into c[], b[], or v[] */
-        huft_t *q;                              /* points to current table */
-        huft_t r;                               /* table entry for structure assignment */
-        huft_t *u[BMAX];                /* table stack */
-        unsigned v[N_MAX];              /* values in order of bit length */
-        int ws[BMAX+1];                 /* bits decoded stack */
-        int w;                                  /* bits decoded */
-        unsigned x[BMAX + 1];   /* bit offsets, then code stack */
-        unsigned *xp;                   /* pointer into x */
-        int y;                                  /* number of dummy codes added */
-        unsigned z;                             /* number of entries in current table */
+        unsigned a;             /* counter for codes of length k */
+        unsigned c[BMAX + 1];   /* bit length count table */
+        unsigned eob_len;       /* length of end-of-block code (value 256) */
+        unsigned f;             /* i repeats in table every f entries */
+        int g;                  /* maximum code length */
+        int htl;                /* table level */
+        unsigned i;             /* counter, current code */
+        unsigned j;             /* counter */
+        int k;                  /* number of bits in current code */
+        unsigned *p;            /* pointer into c[], b[], or v[] */
+        huft_t *q;              /* points to current table */
+        huft_t r;               /* table entry for structure assignment */
+        huft_t *u[BMAX];        /* table stack */
+        unsigned v[N_MAX];      /* values in order of bit length */
+        int ws[BMAX + 1];       /* bits decoded stack */
+        int w;                  /* bits decoded */
+        unsigned x[BMAX + 1];   /* bit offsets, then code stack */
+        unsigned *xp;           /* pointer into x */
+        int y;                  /* number of dummy codes added */
+        unsigned z;             /* number of entries in current table */
 
         /* Length of EOB code, if any */
         eob_len = n > 256 ? b[256] : BMAX;
 
+        *t = NULL;
+
         /* Generate counts for each bit length */
         memset(c, 0, sizeof(c));
-        p = b;
+        p = (unsigned *) b; /* cast allows us to reuse p for pointing to b */
         i = n;
         do {
                 c[*p]++; /* assume all entries <= BMAX */
-                p++; /* Can't combine with above line (Solaris bug) */
+                p++;     /* can't combine with above line (Solaris bug) */
         } while (--i);
-        if (c[0] == n) { /* null input--all zero length codes */
-                *t = NULL;
+        if (c[0] == n) {  /* null input - all zero length codes */
                 *m = 0;
-                return 2;
+                return 2; 
         }
 
         /* Find minimum and maximum length, bound *m by those */
-        for (j = 1; (c[j] == 0) && (j <= BMAX); j++);
+        for (j = 1; (c[j] == 0) && (j <= BMAX); j++)
+                continue;
         k = j; /* minimum code length */
-        for (i = BMAX; (c[i] == 0) && i; i--);
+        for (i = BMAX; (c[i] == 0) && i; i--)
+                continue;
         g = i; /* maximum code length */
         *m = (*m < j) ? j : ((*m > i) ? i : *m);
 
         /* Adjust last length count to fill out codes, if needed */
         for (y = 1 << j; j < i; j++, y <<= 1) {
                 y -= c[j];
-                if (y < 0) {
+                if (y < 0)
                         return 2; /* bad input: more codes than bits */
-                }
         }
         y -= c[i];
-        if (y < 0) {
+        if (y < 0)
                 return 2;
-        }
         c[i] += y;
 
         /* Generate starting offsets into the value table for each length */
@@ -343,7 +356,7 @@ static int huft_build(unsigned *b, const unsigned n,
         }
 
         /* Make a table of values in order of bit lengths */
-        p = b;
+        p = (unsigned *) b;
         i = 0;
         do {
                 j = *p++;
@@ -353,13 +366,13 @@ static int huft_build(unsigned *b, const unsigned n,
         } while (++i < n);
 
         /* Generate the Huffman codes and for each, make the table entries */
-        x[0] = i = 0;                   /* first Huffman code is zero */
-        p = v;                                  /* grab values in bit order */
-        htl = -1;                               /* no tables yet--level -1 */
-        w = ws[0] = 0;                  /* bits decoded */
-        u[0] = NULL;    /* just to keep compilers happy */
-        q = NULL;       /* ditto */
-        z = 0;                                  /* ditto */
+        x[0] = i = 0;   /* first Huffman code is zero */
+        p = v;          /* grab values in bit order */
+        htl = -1;       /* no tables yet--level -1 */
+        w = ws[0] = 0;  /* bits decoded */
+        u[0] = NULL;    /* just to keep compilers happy */
+        q = NULL;       /* ditto */
+        z = 0;          /* ditto */
 
         /* go through the bit lengths (k already is bits in shortest code) */
         for (; k <= g; k++) {
@@ -442,7 +455,7 @@ static int huft_build(unsigned *b, const unsigned n,
         /* return actual size of base table */
         *m = ws[1];
 
-        /* Return true (1) if we were given an incomplete table */
+        /* Return 1 if we were given an incomplete table */
         return y != 0 && g != 1;
 }
 
@@ -468,10 +481,8 @@ static int huft_build(unsigned *b, const unsigned n,
 #define bd inflate_codes_bd
 #define nn inflate_codes_nn
 #define dd inflate_codes_dd
-static void inflate_codes_setup(STATE_PARAM huft_t * my_tl, huft_t * my_td, const unsigned my_bl, const unsigned my_bd)
+static void inflate_codes_setup(STATE_PARAM unsigned my_bl, unsigned my_bd)
 {
-        tl = my_tl;
-        td = my_td;
         bl = my_bl;
         bd = my_bd;
         /* make local copies of globals */
@@ -488,7 +499,8 @@ static int inflate_codes(STATE_PARAM_ONLY)
         unsigned e;     /* table entry flag/number of extra bits */
         huft_t *t;      /* pointer to table entry */
 
-        if (resume_copy) goto do_copy;
+        if (resume_copy)
+                goto do_copy;
 
         while (1) {                     /* do until end of block */
                 bb = fill_bitbuffer(PASS_STATE bb, &k, bl);
@@ -496,10 +508,8 @@ static int inflate_codes(STATE_PARAM_ONLY)
                 e = t->e;
                 if (e > 16)
                         do {
-                                if (e == 99) {
-//shouldn't we propagate error?
-                                        bb_error_msg_and_die("inflate_codes error 1");
-                                }
+                                if (e == 99)
+                                        abort_unzip(PASS_STATE_ONLY);;
                                 bb >>= t->b;
                                 k -= t->b;
                                 e -= 16;
@@ -536,8 +546,7 @@ static int inflate_codes(STATE_PARAM_ONLY)
                         if (e > 16)
                                 do {
                                         if (e == 99)
-//shouldn't we propagate error?
-                                                bb_error_msg_and_die("inflate_codes error 2");
+                                                abort_unzip(PASS_STATE_ONLY);
                                         bb >>= t->b;
                                         k -= t->b;
                                         e -= 16;
@@ -592,9 +601,8 @@ static int inflate_codes(STATE_PARAM_ONLY)
         gunzip_bk = k;
 
         /* normally just after call to inflate_codes, but save code by putting it here */
-        /* free the decoding tables, return */
-        huft_free(tl);
-        huft_free(td);
+        /* free the decoding tables (tl and td), return */
+        huft_free_all(PASS_STATE_ONLY);
 
         /* done */
         return 0;
@@ -634,7 +642,7 @@ static int inflate_stored(STATE_PARAM_ONLY)
                         inflate_stored_w = 0;
                         inflate_stored_b >>= 8;
                         inflate_stored_k -= 8;
-                        return 1; // We have a block
+                        return 1; /* We have a block */
                 }
                 inflate_stored_b >>= 8;
                 inflate_stored_k -= 8;
@@ -644,7 +652,7 @@ static int inflate_stored(STATE_PARAM_ONLY)
         gunzip_outbuf_count = inflate_stored_w;         /* restore global gunzip_window pointer */
         gunzip_bb = inflate_stored_b;   /* restore global bit buffer */
         gunzip_bk = inflate_stored_k;
-        return 0; // Finished
+        return 0; /* Finished */
 }
 
 
@@ -658,9 +666,10 @@ static int inflate_stored(STATE_PARAM_ONLY)
 /* One callsite in inflate_get_next_window */
 static int inflate_block(STATE_PARAM smallint *e)
 {
-        unsigned t;                     /* block type */
-        unsigned b;     /* bit buffer */
-        unsigned k;     /* number of bits in bit buffer */
+        unsigned ll[286 + 30];  /* literal/length and distance code lengths */
+        unsigned t;     /* block type */
+        unsigned b;     /* bit buffer */
+        unsigned k;     /* number of bits in bit buffer */
 
         /* make local bit buffer */
 
@@ -683,9 +692,13 @@ static int inflate_block(STATE_PARAM smallint *e)
         gunzip_bb = b;
         gunzip_bk = k;
 
+        /* Do we see block type 1 often? Yes!
+         * TODO: fix performance problem (see below) */
+        //bb_error_msg("blktype %d", t);
+
         /* inflate that block type */
         switch (t) {
-        case 0:                 /* Inflate stored */
+        case 0: /* Inflate stored */
         {
                 unsigned n;     /* number of bytes in block */
                 unsigned b_stored;      /* bit buffer */
@@ -708,86 +721,73 @@ static int inflate_block(STATE_PARAM smallint *e)
 
                 b_stored = fill_bitbuffer(PASS_STATE b_stored, &k_stored, 16);
                 if (n != (unsigned) ((~b_stored) & 0xffff)) {
-                        return 1;       /* error in compressed data */
+                        abort_unzip(PASS_STATE_ONLY);   /* error in compressed data */
                 }
                 b_stored >>= 16;
                 k_stored -= 16;
 
-                inflate_stored_setup(PASS_STATE n, b_stored, k_stored); // Setup inflate_stored
+                inflate_stored_setup(PASS_STATE n, b_stored, k_stored);
 
                 return -1;
         }
         case 1:
         /* Inflate fixed
-         * decompress an inflated type 1 (fixed Huffman codes) block.  We should
+         * decompress an inflated type 1 (fixed Huffman codes) block. We should
          * either replace this with a custom decoder, or at least precompute the
-         * Huffman tables. */
+         * Huffman tables. TODO */
         {
-                int i;                  /* temporary variable */
-                huft_t *tl;             /* literal/length code table */
-                huft_t *td;             /* distance code table */
-                unsigned bl;                    /* lookup bits for tl */
-                unsigned bd;                    /* lookup bits for td */
-                unsigned l[288];        /* length list for huft_build */
+                int i;                  /* temporary variable */
+                unsigned bl;            /* lookup bits for tl */
+                unsigned bd;            /* lookup bits for td */
+                /* gcc 4.2.1 is too dumb to reuse stackspace. Moved up... */
+                //unsigned ll[288];     /* length list for huft_build */
 
                 /* set up literal table */
-                for (i = 0; i < 144; i++) {
-                        l[i] = 8;
-                }
-                for (; i < 256; i++) {
-                        l[i] = 9;
-                }
-                for (; i < 280; i++) {
-                        l[i] = 7;
-                }
-                for (; i < 288; i++) {  /* make a complete, but wrong code set */
-                        l[i] = 8;
-                }
+                for (i = 0; i < 144; i++)
+                        ll[i] = 8;
+                for (; i < 256; i++)
+                        ll[i] = 9;
+                for (; i < 280; i++)
+                        ll[i] = 7;
+                for (; i < 288; i++) /* make a complete, but wrong code set */
+                        ll[i] = 8;
                 bl = 7;
-                i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl);
-                if (i != 0) {
-                        return i;
-                }
+                huft_build(ll, 288, 257, cplens, cplext, &inflate_codes_tl, &bl);
+                /* huft_build() never return nonzero - we use known data */
 
                 /* set up distance table */
-                for (i = 0; i < 30; i++) {      /* make an incomplete code set */
-                        l[i] = 5;
-                }
+                for (i = 0; i < 30; i++) /* make an incomplete code set */
+                        ll[i] = 5;
                 bd = 5;
-                i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd);
-                if (i > 1) {
-                        huft_free(tl);
-                        return i;
-                }
+                huft_build(ll, 30, 0, cpdist, cpdext, &inflate_codes_td, &bd);
 
-                /* decompress until an end-of-block code */
-                inflate_codes_setup(PASS_STATE tl, td, bl, bd); // Setup inflate_codes
+                /* set up data for inflate_codes() */
+                inflate_codes_setup(PASS_STATE bl, bd);
 
                 /* huft_free code moved into inflate_codes */
 
                 return -2;
         }
-        case 2:                 /* Inflate dynamic */
+        case 2: /* Inflate dynamic */
         {
-                const int dbits = 6;    /* bits in base distance lookup table */
-                const int lbits = 9;    /* bits in base literal/length lookup table */
+                enum { dbits = 6 };     /* bits in base distance lookup table */
+                enum { lbits = 9 };     /* bits in base literal/length lookup table */
 
-                huft_t *tl;             /* literal/length code table */
-                huft_t *td;             /* distance code table */
-                unsigned i;                     /* temporary variables */
+                huft_t *td;             /* distance code table */
+                unsigned i;             /* temporary variables */
                 unsigned j;
-                unsigned l;             /* last length */
-                unsigned m;             /* mask for bit lengths table */
-                unsigned n;             /* number of lengths to get */
-                unsigned bl;                    /* lookup bits for tl */
-                unsigned bd;                    /* lookup bits for td */
-                unsigned nb;    /* number of bit length codes */
-                unsigned nl;    /* number of literal/length codes */
-                unsigned nd;    /* number of distance codes */
-
-                unsigned ll[286 + 30];  /* literal/length and distance code lengths */
-                unsigned b_dynamic;     /* bit buffer */
-                unsigned k_dynamic;     /* number of bits in bit buffer */
+                unsigned l;             /* last length */
+                unsigned m;             /* mask for bit lengths table */
+                unsigned n;             /* number of lengths to get */
+                unsigned bl;            /* lookup bits for tl */
+                unsigned bd;            /* lookup bits for td */
+                unsigned nb;            /* number of bit length codes */
+                unsigned nl;            /* number of literal/length codes */
+                unsigned nd;            /* number of distance codes */
+
+                //unsigned ll[286 + 30];/* literal/length and distance code lengths */
+                unsigned b_dynamic;     /* bit buffer */
+                unsigned k_dynamic;     /* number of bits in bit buffer */
 
                 /* make local bit buffer */
                 b_dynamic = gunzip_bb;
@@ -809,9 +809,8 @@ static int inflate_block(STATE_PARAM smallint *e)
 
                 b_dynamic >>= 4;
                 k_dynamic -= 4;
-                if (nl > 286 || nd > 30) {
-                        return 1;       /* bad lengths */
-                }
+                if (nl > 286 || nd > 30)
+                        abort_unzip(PASS_STATE_ONLY);   /* bad lengths */
 
                 /* read in bit-length-code lengths */
                 for (j = 0; j < nb; j++) {
@@ -820,18 +819,14 @@ static int inflate_block(STATE_PARAM smallint *e)
                         b_dynamic >>= 3;
                         k_dynamic -= 3;
                 }
-                for (; j < 19; j++) {
+                for (; j < 19; j++)
                         ll[border[j]] = 0;
-                }
 
-                /* build decoding table for trees--single level, 7 bit lookup */
+                /* build decoding table for trees - single level, 7 bit lookup */
                 bl = 7;
-                i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl);
+                i = huft_build(ll, 19, 19, NULL, NULL, &inflate_codes_tl, &bl);
                 if (i != 0) {
-                        if (i == 1) {
-                                huft_free(tl);
-                        }
-                        return i;       /* incomplete code set */
+                        abort_unzip(PASS_STATE_ONLY); //return i;       /* incomplete code set */
                 }
 
                 /* read in literal and distance code lengths */
@@ -840,7 +835,8 @@ static int inflate_block(STATE_PARAM smallint *e)
                 i = l = 0;
                 while ((unsigned) i < n) {
                         b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, (unsigned)bl);
-                        j = (td = tl + ((unsigned) b_dynamic & m))->b;
+                        td = inflate_codes_tl + ((unsigned) b_dynamic & m);
+                        j = td->b;
                         b_dynamic >>= j;
                         k_dynamic -= j;
                         j = td->v.n;
@@ -852,7 +848,7 @@ static int inflate_block(STATE_PARAM smallint *e)
                                 b_dynamic >>= 2;
                                 k_dynamic -= 2;
                                 if ((unsigned) i + j > n) {
-                                        return 1;
+                                        abort_unzip(PASS_STATE_ONLY); //return 1;
                                 }
                                 while (j--) {
                                         ll[i++] = l;
@@ -863,7 +859,7 @@ static int inflate_block(STATE_PARAM smallint *e)
                                 b_dynamic >>= 3;
                                 k_dynamic -= 3;
                                 if ((unsigned) i + j > n) {
-                                        return 1;
+                                        abort_unzip(PASS_STATE_ONLY); //return 1;
                                 }
                                 while (j--) {
                                         ll[i++] = 0;
@@ -875,7 +871,7 @@ static int inflate_block(STATE_PARAM smallint *e)
                                 b_dynamic >>= 7;
                                 k_dynamic -= 7;
                                 if ((unsigned) i + j > n) {
-                                        return 1;
+                                        abort_unzip(PASS_STATE_ONLY); //return 1;
                                 }
                                 while (j--) {
                                         ll[i++] = 0;
@@ -885,7 +881,7 @@ static int inflate_block(STATE_PARAM smallint *e)
                 }
 
                 /* free decoding table for trees */
-                huft_free(tl);
+                huft_free(inflate_codes_tl);
 
                 /* restore the global bit buffer */
                 gunzip_bb = b_dynamic;
@@ -894,39 +890,23 @@ static int inflate_block(STATE_PARAM smallint *e)
                 /* build the decoding tables for literal/length and distance codes */
                 bl = lbits;
 
-                i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl);
-                if (i != 0) {
-                        if (i == 1) {
-//shouldn't we propagate error?
-                                bb_error_msg_and_die("incomplete literal tree");
-                                /* huft_free(tl); */
-                        }
-                        return i;       /* incomplete code set */
-                }
-
+                i = huft_build(ll, nl, 257, cplens, cplext, &inflate_codes_tl, &bl);
+                if (i != 0)
+                        abort_unzip(PASS_STATE_ONLY);
                 bd = dbits;
-                i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd);
-                if (i != 0) {
-                        if (i == 1) {
-//shouldn't we propagate error?
-                                bb_error_msg_and_die("incomplete distance tree");
-                                /* huft_free(td); */
-                        }
-                        huft_free(tl);
-                        return i;       /* incomplete code set */
-                }
+                i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &inflate_codes_td, &bd);
+                if (i != 0)
+                        abort_unzip(PASS_STATE_ONLY);
 
-                /* decompress until an end-of-block code */
-                inflate_codes_setup(PASS_STATE tl, td, bl, bd); // Setup inflate_codes
+                /* set up data for inflate_codes() */
+                inflate_codes_setup(PASS_STATE bl, bd);
 
                 /* huft_free code moved into inflate_codes */
 
                 return -2;
         }
         default:
-                /* bad block type */
-//shouldn't we propagate error?
-                bb_error_msg_and_die("bad block type %d", t);
+                abort_unzip(PASS_STATE_ONLY);
         }
 }
 
@@ -952,7 +932,7 @@ static int inflate_get_next_window(STATE_PARAM_ONLY)
                         if (end_reached) {
                                 calculate_gunzip_crc(PASS_STATE_ONLY);
                                 end_reached = 0;
-                                need_another_block = 1;
+                                /* NB: need_another_block is still set */
                                 return 0; /* Last block */
                         }
                         method = inflate_block(PASS_STATE &end_reached);
@@ -966,23 +946,21 @@ static int inflate_get_next_window(STATE_PARAM_ONLY)
                 case -2:
                         ret = inflate_codes(PASS_STATE_ONLY);
                         break;
-                default:
-//shouldn't we propagate error?
-                        bb_error_msg_and_die("inflate error %d", method);
+                default: /* cannot happen */
+                        abort_unzip(PASS_STATE_ONLY);
                 }
 
                 if (ret == 1) {
                         calculate_gunzip_crc(PASS_STATE_ONLY);
-                        return 1; // More data left
+                        return 1; /* more data left */
                 }
-                need_another_block = 1; // End of that block
+                need_another_block = 1; /* end of that block */
         }
         /* Doesnt get here */
 }
 
 
 /* Called from unpack_gz_stream() and inflate_unzip() */
-/* NB: bytebuffer is allocated here but freeing it is left to the caller! */
 static USE_DESKTOP(long long) int
 inflate_unzip_internal(STATE_PARAM int in, int out)
 {
@@ -995,7 +973,10 @@ inflate_unzip_internal(STATE_PARAM int in, int out)
         gunzip_bytes_out = 0;
         gunzip_src_fd = in;
 
-        /* initialize gunzip_window, bit buffer */
+        /* (re) initialize state */
+        method = -1;
+        need_another_block = 1;
+        resume_copy = 0;
         gunzip_bk = 0;
         gunzip_bb = 0;
 
@@ -1003,8 +984,12 @@ inflate_unzip_internal(STATE_PARAM int in, int out)
         gunzip_crc_table = crc32_filltable(NULL, 0);
         gunzip_crc = ~0;
 
-        /* Allocate space for buffer */
-        bytebuffer = xmalloc(bytebuffer_max);
+        error_msg = "corrupted data";
+        if (setjmp(error_jmp)) {
+                /* Error from deep inside zip machinery */
+                n = -1;
+                goto ret;
+        }
 
         while (1) {
                 int r = inflate_get_next_window(PASS_STATE_ONLY);
@@ -1035,6 +1020,10 @@ inflate_unzip_internal(STATE_PARAM int in, int out)
 }
 
 
+/* External entry points */
+
+/* For unzip */
+
 USE_DESKTOP(long long) int
 inflate_unzip(inflate_unzip_result *res, unsigned bufsize, int in, int out)
 {
@@ -1043,60 +1032,196 @@ inflate_unzip(inflate_unzip_result *res, unsigned bufsize, int in, int out)
 
         ALLOC_STATE;
 
-        bytebuffer_max = bufsize + 8;
+        bytebuffer_max = bufsize + 4;
         bytebuffer_offset = 4;
+        bytebuffer = xmalloc(bytebuffer_max);
         n = inflate_unzip_internal(PASS_STATE in, out);
+        free(bytebuffer);
 
         res->crc = gunzip_crc;
         res->bytes_out = gunzip_bytes_out;
-        free(bytebuffer);
         DEALLOC_STATE;
         return n;
 }
 
 
+/* For gunzip */
+
+/* helpers first */
+
+/* Top up the input buffer with at least n bytes. */
+static int top_up(STATE_PARAM unsigned n)
+{
+        int count = bytebuffer_size - bytebuffer_offset;
+
+        if (count < n) {
+                memmove(bytebuffer, &bytebuffer[bytebuffer_offset], count);
+                bytebuffer_offset = 0;
+                bytebuffer_size = full_read(gunzip_src_fd, &bytebuffer[count], bytebuffer_max - count);
+                if ((int)bytebuffer_size < 0) {
+                        bb_error_msg("read error");
+                        return 0;
+                }
+                bytebuffer_size += count;
+                if (bytebuffer_size < n)
+                        return 0;
+        }
+        return 1;
+}
+
+static uint16_t buffer_read_le_u16(STATE_PARAM_ONLY)
+{
+        uint16_t res;
+#if BB_LITTLE_ENDIAN
+        /* gcc 4.2.1 is very clever */
+        memcpy(&res, &bytebuffer[bytebuffer_offset], 2);
+#else
+        res = bytebuffer[bytebuffer_offset];
+        res |= bytebuffer[bytebuffer_offset + 1] << 8;
+#endif
+        bytebuffer_offset += 2;
+        return res;
+}
+
+static uint32_t buffer_read_le_u32(STATE_PARAM_ONLY)
+{
+        uint32_t res;
+#if BB_LITTLE_ENDIAN
+        memcpy(&res, &bytebuffer[bytebuffer_offset], 4);
+#else
+        res = bytebuffer[bytebuffer_offset];
+        res |= bytebuffer[bytebuffer_offset + 1] << 8;
+        res |= bytebuffer[bytebuffer_offset + 2] << 16;
+        res |= bytebuffer[bytebuffer_offset + 3] << 24;
+#endif
+        bytebuffer_offset += 4;
+        return res;
+}
+
+static int check_header_gzip(STATE_PARAM_ONLY)
+{
+        union {
+                unsigned char raw[8];
+                struct {
+                        uint8_t gz_method;
+                        uint8_t flags;
+                        //uint32_t mtime; - unused fields
+                        //uint8_t xtra_flags;
+                        //uint8_t os_flags;
+                } formatted; /* packed */
+        } header;
+
+        /*
+         * Rewind bytebuffer. We use the beginning because the header has 8
+         * bytes, leaving enough for unwinding afterwards.
+         */
+        bytebuffer_size -= bytebuffer_offset;
+        memmove(bytebuffer, &bytebuffer[bytebuffer_offset], bytebuffer_size);
+        bytebuffer_offset = 0;
+
+        if (!top_up(PASS_STATE 8))
+                return 0;
+        memcpy(header.raw, &bytebuffer[bytebuffer_offset], 8);
+        bytebuffer_offset += 8;
+
+        /* Check the compression method */
+        if (header.formatted.gz_method != 8) {
+                return 0;
+        }
+
+        if (header.formatted.flags & 0x04) {
+                /* bit 2 set: extra field present */
+                unsigned extra_short;
+
+                if (!top_up(PASS_STATE 2))
+                        return 0;
+                extra_short = buffer_read_le_u16(PASS_STATE_ONLY);
+                if (!top_up(PASS_STATE extra_short))
+                        return 0;
+                /* Ignore extra field */
+                bytebuffer_offset += extra_short;
+        }
+
+        /* Discard original name and file comment if any */
+        /* bit 3 set: original file name present */
+        /* bit 4 set: file comment present */
+        if (header.formatted.flags & 0x18) {
+                while (1) {
+                        do {
+                                if (!top_up(PASS_STATE 1))
+                                        return 0;
+                        } while (bytebuffer[bytebuffer_offset++] != 0);
+                        if ((header.formatted.flags & 0x18) != 0x18)
+                                break;
+                        header.formatted.flags &= ~0x18;
+                }
+        }
+
+        /* Read the header checksum */
+        if (header.formatted.flags & 0x02) {
+                if (!top_up(PASS_STATE 2))
+                        return 0;
+                bytebuffer_offset += 2;
+        }
+        return 1;
+}
+
 USE_DESKTOP(long long) int
 unpack_gz_stream(int in, int out)
 {
-        uint32_t stored_crc = 0;
-        unsigned count;
+        uint32_t v32;
         USE_DESKTOP(long long) int n;
         DECLARE_STATE;
 
-        ALLOC_STATE;
+        n = 0;
 
+        ALLOC_STATE;
         bytebuffer_max = 0x8000;
-        n = inflate_unzip_internal(PASS_STATE in, out);
-
-        if (n < 0) goto ret;
+        bytebuffer = xmalloc(bytebuffer_max);
 
-        /* top up the input buffer with the rest of the trailer */
-        count = bytebuffer_size - bytebuffer_offset;
-        if (count < 8) {
-                xread(in, &bytebuffer[bytebuffer_size], 8 - count);
-//shouldn't we propagate error?
-                bytebuffer_size += 8 - count;
+ again:
+        if (!check_header_gzip(PASS_STATE_ONLY)) {
+                bb_error_msg("corrupted data");
+                n = -1;
+                goto ret;
         }
-        for (count = 0; count != 4; count++) {
-                stored_crc |= (bytebuffer[bytebuffer_offset] << (count * 8));
-                bytebuffer_offset++;
+        n += inflate_unzip_internal(PASS_STATE in, out);
+        if (n < 0)
+                goto ret;
+
+        if (!top_up(PASS_STATE 8)) {
+                bb_error_msg("corrupted data");
+                n = -1;
+                goto ret;
         }
 
         /* Validate decompression - crc */
-        if (stored_crc != (~gunzip_crc)) {
+        v32 = buffer_read_le_u32(PASS_STATE_ONLY);
+        if ((~gunzip_crc) != v32) {
                 bb_error_msg("crc error");
                 n = -1;
                 goto ret;
         }
 
         /* Validate decompression - size */
-        if (gunzip_bytes_out !=
-                (bytebuffer[bytebuffer_offset] | (bytebuffer[bytebuffer_offset+1] << 8) |
-                (bytebuffer[bytebuffer_offset+2] << 16) | (bytebuffer[bytebuffer_offset+3] << 24))
-        ) {
+        v32 = buffer_read_le_u32(PASS_STATE_ONLY);
+        if ((uint32_t)gunzip_bytes_out != v32) {
                 bb_error_msg("incorrect length");
                 n = -1;
         }
+
+        if (!top_up(PASS_STATE 2))
+                goto ret; /* EOF */
+
+        if (bytebuffer[bytebuffer_offset] == 0x1f
+         && bytebuffer[bytebuffer_offset + 1] == 0x8b
+        ) {
+                bytebuffer_offset += 2;
+                goto again;
+        }
+        /* GNU gzip says: */
+        /*bb_error_msg("decompression OK, trailing garbage ignored");*/
+
  ret:
         free(bytebuffer);
         DEALLOC_STATE;
diff --git a/archival/libunarchive/get_header_tar_gz.c b/archival/libunarchive/get_header_tar_gz.c
index 4b9e793bb..dd655f557 100644
--- a/archival/libunarchive/get_header_tar_gz.c
+++ b/archival/libunarchive/get_header_tar_gz.c
@@ -23,8 +23,6 @@ char get_header_tar_gz(archive_handle_t *archive_handle)
         if ((magic[0] != 0x1f) || (magic[1] != 0x8b)) {
                 bb_error_msg_and_die("invalid gzip magic");
         }
-
-        check_header_gzip_or_die(archive_handle->src_fd);
 #endif
 
         archive_handle->src_fd = open_transformer(archive_handle->src_fd, unpack_gz_stream, "gunzip", "gunzip", "-cf", "-", NULL);
diff --git a/archival/rpm.c b/archival/rpm.c
index 4d723b73f..0b7741a15 100644
--- a/archival/rpm.c
+++ b/archival/rpm.c
@@ -229,7 +229,6 @@ static void extract_cpio_gz(int fd)
                                 USE_FEATURE_RPM_BZ2("/bzip")
                                 " magic");
         } else {
-                check_header_gzip_or_die(archive_handle->src_fd);
 #if !BB_MMU
                 /* NOMMU version of open_transformer execs an external unzipper that should
                  * have the file position at the start of the file */
diff --git a/archival/rpm2cpio.c b/archival/rpm2cpio.c
index dcd9265b3..fe71e9867 100644
--- a/archival/rpm2cpio.c
+++ b/archival/rpm2cpio.c
@@ -79,7 +79,6 @@ int rpm2cpio_main(int argc, char **argv)
                 bb_error_msg_and_die("invalid gzip magic");
         }
 
-        check_header_gzip_or_die(rpm_fd);
         if (unpack_gz_stream(rpm_fd, STDOUT_FILENO) < 0) {
                 bb_error_msg("error inflating");
         }
diff --git a/include/unarchive.h b/include/unarchive.h
index 51ec89cc0..3d3965528 100644
--- a/include/unarchive.h
+++ b/include/unarchive.h
@@ -81,8 +81,6 @@ extern void header_skip(const file_header_t *file_header);
 extern void header_list(const file_header_t *file_header);
 extern void header_verbose_list(const file_header_t *file_header);
 
-extern void check_header_gzip_or_die(int src_fd);
-
 extern char get_header_ar(archive_handle_t *archive_handle);
 extern char get_header_cpio(archive_handle_t *archive_handle);
 extern char get_header_tar(archive_handle_t *archive_handle);