Simplify unzip(), remove unused checks and unneccessary variables

3 files changed, 81 insertions, 153 deletions

diff --git a/archival/libunarchive/decompress_unzip.c b/archival/libunarchive/decompress_unzip.c
index c28ca836c..a747baea5 100644
--- a/archival/libunarchive/decompress_unzip.c
+++ b/archival/libunarchive/decompress_unzip.c
@@ -310,12 +310,8 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
                                 z = 1 << j;             /* table entries for j-bit table */
 
                                 /* allocate and link in new table */
-                                if ((q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t))) == NULL) {
-                                        if (h) {
-                                                huft_free(u[0]);
-                                        }
-                                        return 3;       /* not enough memory */
-                                }
+                                q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t));
+
                                 hufts += z + 1; /* track memory usage */
                                 *t = q + 1;             /* link to list for huft_free() */
                                 *(t = &(q->v.t)) = NULL;
@@ -858,6 +854,9 @@ static int inflate(void)
         bk = 0;
         bb = 0;
 
+        /* Create the crc table */
+        make_crc_table();
+
         /* decompress until the last block */
         do {
                 hufts = 0;
@@ -894,16 +893,10 @@ static int inflate(void)
  */
 extern int unzip(FILE *l_in_file, FILE *l_out_file)
 {
-        const int extra_field = 0x04;   /* bit 2 set: extra field present */
-        const int orig_name = 0x08;     /* bit 3 set: original file name present */
-        const int comment = 0x10;       /* bit 4 set: file comment present */
         unsigned char buf[8];   /* extended local header */
         unsigned char flags;    /* compression flags */
-        char magic[2];                  /* magic header */
-        int method;
         typedef void (*sig_type) (int);
-        int exit_code=0;        /* program exit code */
-        int i;
+        unsigned short i;
 
         in_file = l_in_file;
         out_file = l_out_file;
@@ -927,67 +920,49 @@ extern int unzip(FILE *l_in_file, FILE *l_out_file)
         outcnt = 0;
         bytes_out = 0L;
 
-        magic[0] = fgetc(in_file);
-        magic[1] = fgetc(in_file);
-
         /* Magic header for gzip files, 1F 8B = \037\213 */
-        if (memcmp(magic, "\037\213", 2) != 0) {
+        if ((fgetc(in_file) != 0x1F) || (fgetc(in_file) != 0x8b)) { 
                 error_msg("Invalid gzip magic");
                 return EXIT_FAILURE;
         }
 
-        method = (int) fgetc(in_file);
-        if (method != 8) {
-                error_msg("unknown method %d -- get newer version of gzip", method);
-                exit_code = 1;
-                return -1;
+        /* Check the compression method */
+        if (fgetc(in_file) != 8) {
+                error_msg("Unknown compression method");
+                return(-1);
         }
 
         flags = (unsigned char) fgetc(in_file);
 
         /* Ignore time stamp(4), extra flags(1), OS type(1) */
-        for (i = 0; i < 6; i++)
+        for (i = 0; i < 6; i++) {
                 fgetc(in_file);
+        }
 
-        if ((flags & extra_field) != 0) {
-                size_t extra;
-                extra = fgetc(in_file);
-                extra += fgetc(in_file) << 8;
+        if (flags & 0x04) {
+                /* bit 2 set: extra field present */
+                const unsigned short extra = fgetc(in_file) + (fgetc(in_file) << 8);
 
-                for (i = 0; i < extra; i++)
+                for (i = 0; i < extra; i++) {
                         fgetc(in_file);
+                }
         }
 
         /* Discard original name if any */
-        if ((flags & orig_name) != 0) {
+        if (flags & 0x08) {
+                /* bit 3 set: original file name present */
                 while (fgetc(in_file) != 0);    /* null */
         }
 
         /* Discard file comment if any */
-        if ((flags & comment) != 0) {
+        if (flags & 0x10) {
+                /* bit 4 set: file comment present */
                 while (fgetc(in_file) != 0);    /* null */
         }
 
-        if (method < 0) {
-                printf("it failed\n");
-                return(exit_code);              /* error message already emitted */
-        }
-
-        make_crc_table();
-
         /* Decompress */
-        if (method == 8) {
-
-                int res = inflate();
-
-                if (res == 3) {
-                        error_msg(memory_exhausted);
-                } else if (res != 0) {
-                        error_msg("invalid compressed data--format violated");
-                }
-
-        } else {
-                error_msg("internal error, invalid method");
+        if (inflate() != 0) {
+                error_msg("invalid compressed data--format violated");
         }
 
         /* Get the crc and original length
@@ -1023,6 +998,7 @@ extern void gz_close(int gunzip_pid)
         if (waitpid(gunzip_pid, NULL, 0) == -1) {
                 printf("Couldnt wait ?");
         }
-                free(window);
-                free(crc_table);
+
+        free(window);
+        free(crc_table);
 }
diff --git a/archival/libunarchive/unzip.c b/archival/libunarchive/unzip.c
index c28ca836c..a747baea5 100644
--- a/archival/libunarchive/unzip.c
+++ b/archival/libunarchive/unzip.c
@@ -310,12 +310,8 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
                                 z = 1 << j;             /* table entries for j-bit table */
 
                                 /* allocate and link in new table */
-                                if ((q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t))) == NULL) {
-                                        if (h) {
-                                                huft_free(u[0]);
-                                        }
-                                        return 3;       /* not enough memory */
-                                }
+                                q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t));
+
                                 hufts += z + 1; /* track memory usage */
                                 *t = q + 1;             /* link to list for huft_free() */
                                 *(t = &(q->v.t)) = NULL;
@@ -858,6 +854,9 @@ static int inflate(void)
         bk = 0;
         bb = 0;
 
+        /* Create the crc table */
+        make_crc_table();
+
         /* decompress until the last block */
         do {
                 hufts = 0;
@@ -894,16 +893,10 @@ static int inflate(void)
  */
 extern int unzip(FILE *l_in_file, FILE *l_out_file)
 {
-        const int extra_field = 0x04;   /* bit 2 set: extra field present */
-        const int orig_name = 0x08;     /* bit 3 set: original file name present */
-        const int comment = 0x10;       /* bit 4 set: file comment present */
         unsigned char buf[8];   /* extended local header */
         unsigned char flags;    /* compression flags */
-        char magic[2];                  /* magic header */
-        int method;
         typedef void (*sig_type) (int);
-        int exit_code=0;        /* program exit code */
-        int i;
+        unsigned short i;
 
         in_file = l_in_file;
         out_file = l_out_file;
@@ -927,67 +920,49 @@ extern int unzip(FILE *l_in_file, FILE *l_out_file)
         outcnt = 0;
         bytes_out = 0L;
 
-        magic[0] = fgetc(in_file);
-        magic[1] = fgetc(in_file);
-
         /* Magic header for gzip files, 1F 8B = \037\213 */
-        if (memcmp(magic, "\037\213", 2) != 0) {
+        if ((fgetc(in_file) != 0x1F) || (fgetc(in_file) != 0x8b)) { 
                 error_msg("Invalid gzip magic");
                 return EXIT_FAILURE;
         }
 
-        method = (int) fgetc(in_file);
-        if (method != 8) {
-                error_msg("unknown method %d -- get newer version of gzip", method);
-                exit_code = 1;
-                return -1;
+        /* Check the compression method */
+        if (fgetc(in_file) != 8) {
+                error_msg("Unknown compression method");
+                return(-1);
         }
 
         flags = (unsigned char) fgetc(in_file);
 
         /* Ignore time stamp(4), extra flags(1), OS type(1) */
-        for (i = 0; i < 6; i++)
+        for (i = 0; i < 6; i++) {
                 fgetc(in_file);
+        }
 
-        if ((flags & extra_field) != 0) {
-                size_t extra;
-                extra = fgetc(in_file);
-                extra += fgetc(in_file) << 8;
+        if (flags & 0x04) {
+                /* bit 2 set: extra field present */
+                const unsigned short extra = fgetc(in_file) + (fgetc(in_file) << 8);
 
-                for (i = 0; i < extra; i++)
+                for (i = 0; i < extra; i++) {
                         fgetc(in_file);
+                }
         }
 
         /* Discard original name if any */
-        if ((flags & orig_name) != 0) {
+        if (flags & 0x08) {
+                /* bit 3 set: original file name present */
                 while (fgetc(in_file) != 0);    /* null */
         }
 
         /* Discard file comment if any */
-        if ((flags & comment) != 0) {
+        if (flags & 0x10) {
+                /* bit 4 set: file comment present */
                 while (fgetc(in_file) != 0);    /* null */
         }
 
-        if (method < 0) {
-                printf("it failed\n");
-                return(exit_code);              /* error message already emitted */
-        }
-
-        make_crc_table();
-
         /* Decompress */
-        if (method == 8) {
-
-                int res = inflate();
-
-                if (res == 3) {
-                        error_msg(memory_exhausted);
-                } else if (res != 0) {
-                        error_msg("invalid compressed data--format violated");
-                }
-
-        } else {
-                error_msg("internal error, invalid method");
+        if (inflate() != 0) {
+                error_msg("invalid compressed data--format violated");
         }
 
         /* Get the crc and original length
@@ -1023,6 +998,7 @@ extern void gz_close(int gunzip_pid)
         if (waitpid(gunzip_pid, NULL, 0) == -1) {
                 printf("Couldnt wait ?");
         }
-                free(window);
-                free(crc_table);
+
+        free(window);
+        free(crc_table);
 }
diff --git a/libbb/unzip.c b/libbb/unzip.c
index c28ca836c..a747baea5 100644
--- a/libbb/unzip.c
+++ b/libbb/unzip.c
@@ -310,12 +310,8 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
                                 z = 1 << j;             /* table entries for j-bit table */
 
                                 /* allocate and link in new table */
-                                if ((q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t))) == NULL) {
-                                        if (h) {
-                                                huft_free(u[0]);
-                                        }
-                                        return 3;       /* not enough memory */
-                                }
+                                q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t));
+
                                 hufts += z + 1; /* track memory usage */
                                 *t = q + 1;             /* link to list for huft_free() */
                                 *(t = &(q->v.t)) = NULL;
@@ -858,6 +854,9 @@ static int inflate(void)
         bk = 0;
         bb = 0;
 
+        /* Create the crc table */
+        make_crc_table();
+
         /* decompress until the last block */
         do {
                 hufts = 0;
@@ -894,16 +893,10 @@ static int inflate(void)
  */
 extern int unzip(FILE *l_in_file, FILE *l_out_file)
 {
-        const int extra_field = 0x04;   /* bit 2 set: extra field present */
-        const int orig_name = 0x08;     /* bit 3 set: original file name present */
-        const int comment = 0x10;       /* bit 4 set: file comment present */
         unsigned char buf[8];   /* extended local header */
         unsigned char flags;    /* compression flags */
-        char magic[2];                  /* magic header */
-        int method;
         typedef void (*sig_type) (int);
-        int exit_code=0;        /* program exit code */
-        int i;
+        unsigned short i;
 
         in_file = l_in_file;
         out_file = l_out_file;
@@ -927,67 +920,49 @@ extern int unzip(FILE *l_in_file, FILE *l_out_file)
         outcnt = 0;
         bytes_out = 0L;
 
-        magic[0] = fgetc(in_file);
-        magic[1] = fgetc(in_file);
-
         /* Magic header for gzip files, 1F 8B = \037\213 */
-        if (memcmp(magic, "\037\213", 2) != 0) {
+        if ((fgetc(in_file) != 0x1F) || (fgetc(in_file) != 0x8b)) { 
                 error_msg("Invalid gzip magic");
                 return EXIT_FAILURE;
         }
 
-        method = (int) fgetc(in_file);
-        if (method != 8) {
-                error_msg("unknown method %d -- get newer version of gzip", method);
-                exit_code = 1;
-                return -1;
+        /* Check the compression method */
+        if (fgetc(in_file) != 8) {
+                error_msg("Unknown compression method");
+                return(-1);
         }
 
         flags = (unsigned char) fgetc(in_file);
 
         /* Ignore time stamp(4), extra flags(1), OS type(1) */
-        for (i = 0; i < 6; i++)
+        for (i = 0; i < 6; i++) {
                 fgetc(in_file);
+        }
 
-        if ((flags & extra_field) != 0) {
-                size_t extra;
-                extra = fgetc(in_file);
-                extra += fgetc(in_file) << 8;
+        if (flags & 0x04) {
+                /* bit 2 set: extra field present */
+                const unsigned short extra = fgetc(in_file) + (fgetc(in_file) << 8);
 
-                for (i = 0; i < extra; i++)
+                for (i = 0; i < extra; i++) {
                         fgetc(in_file);
+                }
         }
 
         /* Discard original name if any */
-        if ((flags & orig_name) != 0) {
+        if (flags & 0x08) {
+                /* bit 3 set: original file name present */
                 while (fgetc(in_file) != 0);    /* null */
         }
 
         /* Discard file comment if any */
-        if ((flags & comment) != 0) {
+        if (flags & 0x10) {
+                /* bit 4 set: file comment present */
                 while (fgetc(in_file) != 0);    /* null */
         }
 
-        if (method < 0) {
-                printf("it failed\n");
-                return(exit_code);              /* error message already emitted */
-        }
-
-        make_crc_table();
-
         /* Decompress */
-        if (method == 8) {
-
-                int res = inflate();
-
-                if (res == 3) {
-                        error_msg(memory_exhausted);
-                } else if (res != 0) {
-                        error_msg("invalid compressed data--format violated");
-                }
-
-        } else {
-                error_msg("internal error, invalid method");
+        if (inflate() != 0) {
+                error_msg("invalid compressed data--format violated");
         }
 
         /* Get the crc and original length
@@ -1023,6 +998,7 @@ extern void gz_close(int gunzip_pid)
         if (waitpid(gunzip_pid, NULL, 0) == -1) {
                 printf("Couldnt wait ?");
         }
-                free(window);
-                free(crc_table);
+
+        free(window);
+        free(crc_table);
 }