[svn-r17108] Purpose: Fix bug in H5Z_filter_info

Description:
Previously, when H5Z_filter_info was called for a filter that was not present,
it would succeed and return the information from one position past the end of
the pipeline, possibly causing a segfault.  This affected at least
H5Pget_fitler_by_id1/2, and possibly other API functions.  Fixed to properly
return failure.

Tested: jam, linew, smirom (h5committest)

release_docs/RELEASE.txt

@@ -167,6 +167,8 @@ Bug Fixes since HDF5-1.8.0 release
 
     Library
     -------
+      - Fixed a bug where H5Pget_fitler_by_id would succeed when called for a
+            filter that wasn't present. (NAF - 2009/06/25)
       - Fixed an issue with committed compound datatypes containing a vlen.
             Also fixed memory leaks involving committed datatypes.
             (NAF - 2009/06/10 - 1593)

src/H5Z.c

@@ -1115,7 +1115,7 @@ H5Z_filter_info(const H5O_pline_t *pline, H5Z_filter_t filter)
             break;
 
     /* Check if the filter was not already in the pipeline */
-    if(idx>pline->nused)
+    if(idx>=pline->nused)
 	HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, NULL, "filter not in pipeline")
 
     /* Set return value */

test/dsets.c

@@ -5547,6 +5547,7 @@ test_filter_delete(hid_t file)
     hsize_t      dims[2]={20,20};       /* dataspace dimensions */
     hsize_t      chunk_dims[2]={10,10}; /* chunk dimensions */
     int          nfilters;              /* number of filters in DCPL */
+    unsigned     flags;                 /* flags for filter */
     herr_t       ret;                   /* generic return value */
     int          i;
 
@@ -5587,6 +5588,16 @@ test_filter_delete(hid_t file)
             goto error;
     }
 
+    /* try to get the info for the deflate filter */
+    H5E_BEGIN_TRY {
+        ret=H5Pget_filter_by_id2(dcpl1,H5Z_FILTER_DEFLATE,&flags,NULL,NULL,0,NULL,NULL);
+    } H5E_END_TRY;
+    if(ret >=0) {
+        H5_FAILED();
+        printf("    Line %d: Shouldn't have deleted filter!\n",__LINE__);
+        goto error;
+    } /* end if */
+
     /* try to delete the deflate filter again */
     H5E_BEGIN_TRY {
         ret=H5Premove_filter(dcpl1,H5Z_FILTER_DEFLATE);