Fix pg_restore to do the right thing when escaping large objects.

Specifically, this makes the workflow pg_dump -Fc -> pg_restore -> file
produce correct output for BLOBs when the source database has
standard_conforming_strings turned on.  It was already okay when that was
off, or if pg_restore was told to restore directly into a database.

This is a back-port of commit b1732111f233bbb72788e92a627242ec28a85631 of
2009-08-04, with additional changes to emit old-style escaped bytea data
instead of hex-style.  At the time, we had not heard of anyone encountering
the problem in the field, so I judged it not worth the risk of changing
back branches.  Now we do have a report, from Bosco Rama, so back-patch
into 8.2 through 8.4.  9.0 and up are okay already.

diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 48b3fed63a0a7b97b68a74a6ffc7f6ed295876ad..ac2da69faf8399ad9030da30b25765bd1a52844d 100644 (file)
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -261,6 +261,84 @@ appendStringLiteralDQ(PQExpBuffer buf, const char *str, const char *dqprefix)
 }
 
 
+/*
+ * Convert a bytea value (presented as raw bytes) to an SQL string literal
+ * and append it to the given buffer.  We assume the specified
+ * standard_conforming_strings setting.
+ *
+ * This is needed in situations where we do not have a PGconn available.
+ * Where we do, PQescapeByteaConn is a better choice.
+ */
+void
+appendByteaLiteral(PQExpBuffer buf, const unsigned char *str, size_t length,
+                  bool std_strings)
+{
+   const unsigned char *vp;
+   unsigned char *rp;
+   size_t      i;
+   size_t      len;
+   size_t      bslash_len = (std_strings ? 1 : 2);
+
+   len = 2;                    /* for the quote marks */
+   vp = str;
+   for (i = length; i > 0; i--, vp++)
+   {
+       if (*vp < 0x20 || *vp > 0x7e)
+           len += bslash_len + 3;
+       else if (*vp == '\'')
+           len += 2;
+       else if (*vp == '\\')
+           len += bslash_len + bslash_len;
+       else
+           len++;
+   }
+
+   if (!enlargePQExpBuffer(buf, len))
+       return;
+
+   rp = (unsigned char *) (buf->data + buf->len);
+   *rp++ = '\'';
+
+   vp = str;
+   for (i = length; i > 0; i--, vp++)
+   {
+       if (*vp < 0x20 || *vp > 0x7e)
+       {
+           int         val = *vp;
+
+           if (!std_strings)
+               *rp++ = '\\';
+           *rp++ = '\\';
+           *rp++ = (val >> 6) + '0';
+           *rp++ = ((val >> 3) & 07) + '0';
+           *rp++ = (val & 07) + '0';
+       }
+       else if (*vp == '\'')
+       {
+           *rp++ = '\'';
+           *rp++ = '\'';
+       }
+       else if (*vp == '\\')
+       {
+           if (!std_strings)
+           {
+               *rp++ = '\\';
+               *rp++ = '\\';
+           }
+           *rp++ = '\\';
+           *rp++ = '\\';
+       }
+       else
+           *rp++ = *vp;
+   }
+
+   *rp++ = '\'';
+   *rp = '\0';
+
+   buf->len = ((char *) rp) - buf->data;
+}
+
+
 /*
  * Convert backend's version string into a number.
  */

diff --git a/src/bin/pg_dump/dumputils.h b/src/bin/pg_dump/dumputils.h
index 94beade21379aec03d1091fb3641475d9a06ec49..9e3686e1ddc99f0eeda165eee4c8727766e0993d 100644 (file)
--- a/src/bin/pg_dump/dumputils.h
+++ b/src/bin/pg_dump/dumputils.h
@@ -26,6 +26,9 @@ extern void appendStringLiteralConn(PQExpBuffer buf, const char *str,
                        PGconn *conn);
 extern void appendStringLiteralDQ(PQExpBuffer buf, const char *str,
                      const char *dqprefix);
+extern void appendByteaLiteral(PQExpBuffer buf,
+                              const unsigned char *str, size_t length,
+                              bool std_strings);
 extern int parse_version(const char *versionString);
 extern bool parsePGArray(const char *atext, char ***itemarray, int *nitems);
 extern bool buildACLCommands(const char *name, const char *type,

diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 67c72ab2df36f214966b762d5748468a8c9fc899..5982d171a4aa44c894976e8bfdae9d29eb3698ca 100644 (file)
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -1058,20 +1058,19 @@ dump_lo_buf(ArchiveHandle *AH)
    }
    else
    {
-       unsigned char *str;
-       size_t      len;
+       PQExpBuffer buf = createPQExpBuffer();
 
-       str = PQescapeBytea((const unsigned char *) AH->lo_buf,
-                           AH->lo_buf_used, &len);
-       if (!str)
-           die_horribly(AH, modulename, "out of memory\n");
+       appendByteaLiteralAHX(buf,
+                             (const unsigned char *) AH->lo_buf,
+                             AH->lo_buf_used,
+                             AH);
 
        /* Hack: turn off writingBlob so ahwrite doesn't recurse to here */
        AH->writingBlob = 0;
-       ahprintf(AH, "SELECT lowrite(0, '%s');\n", str);
+       ahprintf(AH, "SELECT pg_catalog.lowrite(0, %s);\n", buf->data);
        AH->writingBlob = 1;
 
-       free(str);
+       destroyPQExpBuffer(buf);
    }
    AH->lo_buf_used = 0;
 }

diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 55cb156132c054fb29493a9cc1bbc42bd4779b42..67ffe9c2d141a7507c117b21626f9a1439a40de9 100644 (file)
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -329,6 +329,9 @@ extern bool checkSeek(FILE *fp);
 #define appendStringLiteralAHX(buf,str,AH) \
    appendStringLiteral(buf, str, (AH)->public.encoding, (AH)->public.std_strings)
 
+#define appendByteaLiteralAHX(buf,str,len,AH) \
+   appendByteaLiteral(buf, str, len, (AH)->public.std_strings)
+
 /*
  * Mandatory routines for each supported format
  */

diff --git a/src/bin/pg_dump/pg_backup_null.c b/src/bin/pg_dump/pg_backup_null.c
index f31a173ce1fe3baea83567c73cbb945179503ff3..84bbf3ac6b3050a86d674b3aaa17e864bf4c54dd 100644 (file)
--- a/src/bin/pg_dump/pg_backup_null.c
+++ b/src/bin/pg_dump/pg_backup_null.c
@@ -23,6 +23,7 @@
  */
 
 #include "pg_backup_archiver.h"
+#include "dumputils.h"
 
 #include <unistd.h>                /* for dup */
 
@@ -98,16 +99,16 @@ _WriteBlobData(ArchiveHandle *AH, const void *data, size_t dLen)
 {
    if (dLen > 0)
    {
-       unsigned char *str;
-       size_t      len;
+       PQExpBuffer buf = createPQExpBuffer();
 
-       str = PQescapeBytea((const unsigned char *) data, dLen, &len);
-       if (!str)
-           die_horribly(AH, NULL, "out of memory\n");
+       appendByteaLiteralAHX(buf,
+                             (const unsigned char *) data,
+                             dLen,
+                             AH);
 
-       ahprintf(AH, "SELECT lowrite(0, '%s');\n", str);
+       ahprintf(AH, "SELECT pg_catalog.lowrite(0, %s);\n", buf->data);
 
-       free(str);
+       destroyPQExpBuffer(buf);
    }
    return dLen;
 }