Fix assorted infelicities in new SetWALSegSize() function.

* Failure to check for malloc failure (ok, pretty unlikely here, but
that's not an excuse).

* Leakage of open fd on read error, and of malloc'd buffer always.

* Incorrect assumption that a short read would set errno to zero.

* Failure to adhere to message style conventions (in particular,
not reporting errno where relevant; using "couldn't open" rather than
"could not open" is not really in line with project style either).

* Missing newlines on some messages.

Coverity spotted the leak problems; I noticed the rest while
fixing the leaks.

diff --git a/contrib/pg_standby/pg_standby.c b/contrib/pg_standby/pg_standby.c
index 6aeca6e8f72acd35e763cc8a9001cc1848e01dcf..cb785971a98f346ee30326d3ce1d760636453d7f 100644 (file)
--- a/contrib/pg_standby/pg_standby.c
+++ b/contrib/pg_standby/pg_standby.c
@@ -408,16 +408,21 @@ SetWALSegSize(void)
 {
        bool            ret_val = false;
        int                     fd;
-       char       *buf = (char *) malloc(XLOG_BLCKSZ);
+
+       /* malloc this buffer to ensure sufficient alignment: */
+       char       *buf = (char *) pg_malloc(XLOG_BLCKSZ);
 
        Assert(WalSegSz == -1);
 
        if ((fd = open(WALFilePath, O_RDWR, 0)) < 0)
        {
-               fprintf(stderr, "%s: couldn't open WAL file \"%s\"\n",
-                               progname, WALFilePath);
+               fprintf(stderr, "%s: could not open WAL file \"%s\": %s\n",
+                               progname, WALFilePath, strerror(errno));
+               pg_free(buf);
                return false;
        }
+
+       errno = 0;
        if (read(fd, buf, XLOG_BLCKSZ) == XLOG_BLCKSZ)
        {
                XLogLongPageHeader longhdr = (XLogLongPageHeader) buf;
@@ -433,7 +438,6 @@ SetWALSegSize(void)
                        fprintf(stderr,
                                        "%s: WAL segment size must be a power of two between 1MB and 1GB, but the WAL file header specifies %d bytes\n",
                                        progname, WalSegSz);
-               close(fd);
        }
        else
        {
@@ -444,17 +448,21 @@ SetWALSegSize(void)
                if (errno != 0)
                {
                        if (debug)
-                               fprintf(stderr, "could not read file \"%s\": %s",
+                               fprintf(stderr, "could not read file \"%s\": %s\n",
                                                WALFilePath, strerror(errno));
                }
                else
                {
                        if (debug)
-                               fprintf(stderr, "not enough data in file \"%s\"", WALFilePath);
+                               fprintf(stderr, "not enough data in file \"%s\"\n",
+                                               WALFilePath);
                }
        }
 
        fflush(stderr);
+
+       close(fd);
+       pg_free(buf);
        return ret_val;
 }