Fix append of zero-length records to zero-length records.

[ccan] / ccan / tdb / tdb.c

diff --git a/ccan/tdb/tdb.c b/ccan/tdb/tdb.c
index 9cc51eaacfbca2858b10c0b940817abfd4deda00..db5e5b49e4b663eeb290401d7346342d870b6a28 100644 (file)
--- a/ccan/tdb/tdb.c
+++ b/ccan/tdb/tdb.c
@@ -65,8 +65,6 @@ static void tdb_increment_seqnum(struct tdb_context *tdb)
                return;
        }
 
-       tdb_trace(tdb, "tdb_increment_seqnum");
-
        tdb_increment_seqnum_nonblock(tdb);
 
        tdb_brlock(tdb, TDB_SEQNUM_OFS, F_UNLCK, F_SETLKW, 1, 1);
@@ -417,7 +415,7 @@ int tdb_delete(struct tdb_context *tdb, TDB_DATA key)
        ret = tdb_delete_hash(tdb, key, hash);
        tdb_trace(tdb, "tdb_delete ");
        tdb_trace_record(tdb, key);
-       tdb_trace(tdb, "= %i\n", ret); 
+       tdb_trace(tdb, "= %s\n", ret ? "ENOENT" : "0"); 
        return ret;
 }
 
@@ -625,8 +623,13 @@ int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf)
        if (dbuf.dptr == NULL) {
                dbuf.dptr = (unsigned char *)malloc(new_dbuf.dsize);
        } else {
-               unsigned char *new_dptr = (unsigned char *)realloc(dbuf.dptr,
-                                                    dbuf.dsize + new_dbuf.dsize);
+               unsigned int new_len = dbuf.dsize + new_dbuf.dsize;
+               unsigned char *new_dptr;
+
+               /* realloc '0' is special: don't do that. */
+               if (new_len == 0)
+                       new_len = 1;
+               new_dptr = (unsigned char *)realloc(dbuf.dptr, new_len);
                if (new_dptr == NULL) {
                        free(dbuf.dptr);
                }
@@ -693,8 +696,8 @@ int tdb_get_seqnum(struct tdb_context *tdb)
 {
        tdb_off_t seqnum=0;
 
-       tdb_trace(tdb, "tdb_get_seqnum\n");
        tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum);
+       tdb_trace(tdb, "tdb_get_seqnum = %u\n", seqnum);
        return seqnum;
 }
 
@@ -857,23 +860,25 @@ void tdb_trace(const struct tdb_context *tdb, const char *fmt, ...)
 {
        char msg[256];
        va_list args;
-       int len;
+       int len, err;
 
        va_start(args, fmt);
        len = vsprintf(msg, fmt, args);
        va_end(args);
 
-       write(tdb->tracefd, msg, len);
+       err = write(tdb->tracefd, msg, len);
 }
 
 void tdb_trace_record(const struct tdb_context *tdb, TDB_DATA rec)
 {
        char msg[20];
        unsigned int i;
+       int err;
 
-       write(tdb->tracefd, msg, sprintf(msg, "%zu:", rec.dsize));
+       err = write(tdb->tracefd, msg, sprintf(msg, "%zu:", rec.dsize));
        for (i = 0; i < rec.dsize; i++)
-               write(tdb->tracefd, msg, sprintf(msg, "%02x", rec.dptr[i]));
-       write(tdb->tracefd, " ", 1);
+               err += write(tdb->tracefd, msg, sprintf(msg, "%02x",
+                                                       rec.dptr[i]));
+       err += write(tdb->tracefd, " ", 1);
 }
 #endif