[PATCH 35/36] sha1_file: introduce a constant for max header length

[brian m. carlson]

There were several instances of 32 sprinkled throughout this file, all
of which were used for allocating a buffer to store the header of an
object.  Introduce a constant, MAX_HEADER_LEN, for this purpose.

Note that this constant is slightly larger than required; the longest
possible header is 28 (7 for "commit", 1 for a space, 20 for a 63-bit
length in decimal, and 1 for the NUL).  However, the overallocation
should not cause any problems, so leave it as it is.

Signed-off-by: brian m. carlson <sand...@crustytoothpaste.net>
---
 sha1_file.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/sha1_file.c b/sha1_file.c
index c41fbe2f01..4d4f9248c7 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -30,6 +30,9 @@
 #include "packfile.h"
 #include "fetch-object.h"
 
+/* The maximum size for an object header. */
+#define MAX_HEADER_LEN 32
+
 const unsigned char null_sha1[GIT_MAX_RAWSZ];
 const struct object_id null_oid;
 const struct object_id empty_tree_oid = {
@@ -791,7 +794,7 @@ int check_object_signature(const struct object_id *oid, 
void *map,
        enum object_type obj_type;
        struct git_istream *st;
        git_hash_ctx c;
-       char hdr[32];
+       char hdr[MAX_HEADER_LEN];
        int hdrlen;
 
        if (map) {
@@ -1150,7 +1153,7 @@ static int sha1_loose_object_info(const unsigned char 
*sha1,
        unsigned long mapsize;
        void *map;
        git_zstream stream;
-       char hdr[32];
+       char hdr[MAX_HEADER_LEN];
        struct strbuf hdrbuf = STRBUF_INIT;
        unsigned long size_scratch;
 
@@ -1512,7 +1515,7 @@ static int write_buffer(int fd, const void *buf, size_t 
len)
 int hash_object_file(const void *buf, unsigned long len, const char *type,
                     struct object_id *oid)
 {
-       char hdr[32];
+       char hdr[MAX_HEADER_LEN];
        int hdrlen = sizeof(hdr);
        write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
        return 0;
@@ -1667,7 +1670,7 @@ static int freshen_packed_object(const unsigned char 
*sha1)
 int write_object_file(const void *buf, unsigned long len, const char *type,
                      struct object_id *oid)
 {
-       char hdr[32];
+       char hdr[MAX_HEADER_LEN];
        int hdrlen = sizeof(hdr);
 
        /* Normally if we have it in the pack then we do not bother writing
@@ -1687,7 +1690,7 @@ int hash_object_file_literally(const void *buf, unsigned 
long len,
        int hdrlen, status = 0;
 
        /* type string, SP, %lu of the length plus NUL must fit this */
-       hdrlen = strlen(type) + 32;
+       hdrlen = strlen(type) + MAX_HEADER_LEN;
        header = xmalloc(hdrlen);
        write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
 
@@ -1707,7 +1710,7 @@ int force_object_loose(const struct object_id *oid, 
time_t mtime)
        void *buf;
        unsigned long len;
        enum object_type type;
-       char hdr[32];
+       char hdr[MAX_HEADER_LEN];
        int hdrlen;
        int ret;
 
@@ -2189,7 +2192,7 @@ int read_loose_object(const char *path,
        void *map = NULL;
        unsigned long mapsize;
        git_zstream stream;
-       char hdr[32];
+       char hdr[MAX_HEADER_LEN];
 
        *contents = NULL;