Fix coredump due to writing one more byte than we'd allocated.

diff --git a/src/bin/pg_dump/pg_backup_custom.c b/src/bin/pg_dump/pg_backup_custom.c
index 94c598c51b4dc041ccd53bae8c0108f285824aae..4fe74a1bc682cb888f9a76343bd5d36a6d1d7f7f 100644 (file)
--- a/src/bin/pg_dump/pg_backup_custom.c
+++ b/src/bin/pg_dump/pg_backup_custom.c
@@ -150,7 +150,14 @@ void InitArchiveFmt_Custom(ArchiveHandle* AH)
     if (ctx->zp == NULL)
    die_horribly(AH, "%s: unable to allocate zlib stream archive context",progname);
 
-    ctx->zlibOut = (char*)malloc(zlibOutSize);
+   /*
+    * zlibOutSize is the buffer size we tell zlib it can output to.  We
+    * actually allocate one extra byte because some routines want to append
+    * a trailing zero byte to the zlib output.  The input buffer is expansible
+    * and is always of size ctx->inSize; zlibInSize is just the initial
+    * default size for it.
+    */
+    ctx->zlibOut = (char*)malloc(zlibOutSize+1);
     ctx->zlibIn = (char*)malloc(zlibInSize);
     ctx->inSize = zlibInSize;
     ctx->filePos = 0;
@@ -518,14 +525,14 @@ static void   _PrintData(ArchiveHandle* AH)
 
     blkLen = ReadInt(AH);
     while (blkLen != 0) {
-       if (blkLen > (ctx->inSize - 1)) {
+       if (blkLen+1 > ctx->inSize) {
            free(ctx->zlibIn);
            ctx->zlibIn = NULL;
-           ctx->zlibIn = (char*)malloc(blkLen);
+           ctx->zlibIn = (char*)malloc(blkLen+1);
            if (!ctx->zlibIn)
                die_horribly(AH, "%s: failed to allocate decompression buffer\n", progname);
 
-           ctx->inSize = blkLen;
+           ctx->inSize = blkLen+1;
            in = ctx->zlibIn;
        }
 
@@ -848,7 +855,7 @@ static void _StartDataCompressor(ArchiveHandle* AH, TocEntry* te)
 
 #endif
 
-    /* Just be paranoid - maye End is called after Start, with no Write */
+    /* Just be paranoid - maybe End is called after Start, with no Write */
     zp->next_out = ctx->zlibOut;
     zp->avail_out = zlibOutSize;
 }
@@ -887,7 +894,7 @@ static int  _DoDeflate(ArchiveHandle* AH, lclContext* ctx, int flush)
                /* printf("Wrote %d byte deflated chunk\n", zlibOutSize - zp->avail_out); */
                WriteInt(AH, zlibOutSize - zp->avail_out);
                if (fwrite(out, 1, zlibOutSize - zp->avail_out, AH->FH) != (zlibOutSize - zp->avail_out))
-                   die_horribly(AH, "%s: could write compressed chunk\n",progname);
+                   die_horribly(AH, "%s: could not write compressed chunk\n",progname);
                ctx->filePos += zlibOutSize - zp->avail_out;
            }
            zp->next_out = out;
@@ -899,7 +906,7 @@ static int  _DoDeflate(ArchiveHandle* AH, lclContext* ctx, int flush)
        {
            WriteInt(AH, zp->avail_in);
            if (fwrite(zp->next_in, 1, zp->avail_in, AH->FH) != zp->avail_in)
-               die_horribly(AH, "%s: could write uncompressed chunk\n", progname);
+               die_horribly(AH, "%s: could not write uncompressed chunk\n", progname);
            ctx->filePos += zp->avail_in;
            zp->avail_in = 0;
        } else {