[svn-r24865] Description:

    - Added another overload for char* argument:
        ssize_t getComment(const char* name, const size_t buf_size, char* comment)
    - Changed default value to 0 for the other two getComment methods
    - Added HDmemset to after every char string allocation to clear the buffer
Platforms tested:
    Linux/ppc64 (ostrich)
    Linux/32 2.6 (jam)
    Linux/64 2.6 (platypus)/PGI compilers

11 files changed, 156 insertions, 61 deletions

diff --git a/c++/src/H5CommonFG.cpp b/c++/src/H5CommonFG.cpp
index 3bf4b4f..fc8b08d 100644
--- a/c++/src/H5CommonFG.cpp
+++ b/c++/src/H5CommonFG.cpp
@@ -436,6 +436,7 @@ H5std_string CommonFG::getLinkval( const char* name, size_t size ) const
     if (val_size > 0)
     {
 	value_C = new char[val_size+1];  // temporary C-string for C API
+	HDmemset(value_C, 0, val_size+1); // clear buffer
 
 	ret_value = H5Lget_val(getLocId(), name, value_C, val_size, H5P_DEFAULT);
 	if( ret_value < 0 )
@@ -881,6 +882,8 @@ H5std_string CommonFG::getObjnameByIdx(hsize_t idx) const
 
     // now, allocate C buffer to get the name
     char* name_C = new char[name_len+1];
+    HDmemset(name_C, 0, name_len+1); // clear buffer
+
     name_len = H5Lget_name_by_idx(getLocId(), ".", H5_INDEX_NAME, H5_ITER_INC, idx, name_C, name_len+1, H5P_DEFAULT);
 
     // clean up and return the string
@@ -924,8 +927,10 @@ ssize_t CommonFG::getObjnameByIdx(hsize_t idx, char* name, size_t size) const
 //--------------------------------------------------------------------------
 ssize_t CommonFG::getObjnameByIdx(hsize_t idx, H5std_string& name, size_t size) const
 {
-   char* name_C = new char[size];
-   ssize_t name_len = getObjnameByIdx(idx, name_C, size);
+   char* name_C = new char[size+1]; // temporary C-string for object name
+   HDmemset(name_C, 0, size+1); // clear buffer
+
+   ssize_t name_len = getObjnameByIdx(idx, name_C, size+1);
    if(name_len < 0)
       throwException("getObjnameByIdx", "H5Lget_name_by_idx failed");
 
diff --git a/c++/src/H5DataSet.cpp b/c++/src/H5DataSet.cpp
index 0722ef9..699f982 100644
--- a/c++/src/H5DataSet.cpp
+++ b/c++/src/H5DataSet.cpp
@@ -629,7 +629,7 @@ hid_t DataSet::getId() const
 
 //--------------------------------------------------------------------------
 // Function:	DataSet::p_read_fixed_len (private)
-// brief	Reads a fixed length \a H5std_string from an dataset.
+// brief	Reads a fixed length \a H5std_string from a dataset.
 // param	mem_type  - IN: DataSet datatype (in memory)
 // param	strg      - IN: Buffer for read string
 // exception	H5::DataSetIException
@@ -643,14 +643,14 @@ void DataSet::p_read_fixed_len(const hid_t mem_type_id, const hid_t mem_space_id
     // Only allocate for fixed-len string.
 
     // Get the size of the dataset's data
-    size_t attr_size = getInMemDataSize();
+    size_t data_size = getInMemDataSize();
 
     // If there is data, allocate buffer and read it.
-    if (attr_size > 0)
+    if (data_size > 0)
     {
-	char *strg_C = NULL;
+	char *strg_C = new char [data_size+1];
+	HDmemset(strg_C, 0, data_size+1); // clear buffer
 
-	strg_C = new char [(size_t)attr_size+1];
 	herr_t ret_value = H5Dread(id, mem_type_id, mem_space_id, file_space_id, xfer_plist_id, strg_C);
 
 	if( ret_value < 0 )
diff --git a/c++/src/H5EnumType.cpp b/c++/src/H5EnumType.cpp
index ff632af..04bb9e0 100644
--- a/c++/src/H5EnumType.cpp
+++ b/c++/src/H5EnumType.cpp
@@ -30,6 +30,7 @@
 #include "H5AtomType.h"
 #include "H5IntType.h"
 #include "H5EnumType.h"
+#include "H5private.h"			// for HDmemset
 
 #ifndef H5_NO_NAMESPACE
 namespace H5 {
@@ -150,6 +151,7 @@ void EnumType::insert( const H5std_string& name, void *value ) const
 H5std_string EnumType::nameOf( void *value, size_t size ) const
 {
    char* name_C = new char[size+1];  // temporary C-string for C API
+   HDmemset(name_C, 0, size+1); // clear buffer
 
    // Calls C routine H5Tenum_nameof to get the name of the specified enum type
    herr_t ret_value = H5Tenum_nameof( id, value, name_C, size );
@@ -160,7 +162,7 @@ H5std_string EnumType::nameOf( void *value, size_t size ) const
       throw DataTypeIException("EnumType::nameOf", "H5Tenum_nameof failed");
    }
    // otherwise, create the string to hold the datatype name and return it
-   H5std_string name = H5std_string(name_C);
+   H5std_string name(name_C);
    delete []name_C;
    return( name );
 }
diff --git a/c++/src/H5Exception.cpp b/c++/src/H5Exception.cpp
index ddc1d00..492abed 100644
--- a/c++/src/H5Exception.cpp
+++ b/c++/src/H5Exception.cpp
@@ -522,6 +522,29 @@ LibraryIException::LibraryIException(const H5std_string& func_name, const H5std_
 LibraryIException::~LibraryIException() throw() {}
 
 //--------------------------------------------------------------------------
+// Subclass:	LocationException
+// Programmer	Binh-Minh Ribler - 2014
+//--------------------------------------------------------------------------
+//--------------------------------------------------------------------------
+// Function:	LocationException default constructor
+///\brief	Default constructor.
+//--------------------------------------------------------------------------
+LocationException::LocationException():Exception(){}
+//--------------------------------------------------------------------------
+// Function:	LocationException overloaded constructor
+///\brief	Creates a LocationException with the name of the function,
+///		in which the failure occurs, and an optional detailed message.
+///\param	func_name - IN: Name of the function where failure occurs
+///\param	message   - IN: Message on the failure
+//--------------------------------------------------------------------------
+LocationException::LocationException(const H5std_string& func_name, const H5std_string& message) : Exception(func_name, message) {}
+//--------------------------------------------------------------------------
+// Function:	LocationException destructor
+///\brief	Noop destructor.
+//--------------------------------------------------------------------------
+LocationException::~LocationException() throw() {}
+
+//--------------------------------------------------------------------------
 // Subclass:	IdComponentException
 // Programmer	Binh-Minh Ribler - 2000
 //--------------------------------------------------------------------------
diff --git a/c++/src/H5Exception.h b/c++/src/H5Exception.h
index d747af3..7d71022 100644
--- a/c++/src/H5Exception.h
+++ b/c++/src/H5Exception.h
@@ -155,6 +155,13 @@ class H5_DLLCPP LibraryIException : public Exception {
 	virtual ~LibraryIException() throw();
 };
 
+class H5_DLLCPP LocationException : public Exception {
+   public:
+	LocationException(const H5std_string& func_name, const H5std_string& message = DEFAULT_MSG);
+	LocationException();
+	virtual ~LocationException() throw();
+};
+
 class H5_DLLCPP IdComponentException : public Exception {
    public:
 	IdComponentException(const H5std_string& func_name, const H5std_string& message = DEFAULT_MSG);
diff --git a/c++/src/H5IdComponent.cpp b/c++/src/H5IdComponent.cpp
index c60d05c..cdf4272 100644
--- a/c++/src/H5IdComponent.cpp
+++ b/c++/src/H5IdComponent.cpp
@@ -25,6 +25,7 @@
 #include "H5Library.h"
 #include "H5IdComponent.h"
 #include "H5DataSpace.h"
+#include "H5private.h"			// for HDmemset
 
 #ifndef H5_NO_NAMESPACE
 namespace H5 {
@@ -289,6 +290,8 @@ H5std_string IdComponent::p_get_file_name() const
 
    // Call H5Fget_name again to get the actual file name
    char* name_C = new char[name_size+1];  // temporary C-string for C API
+   HDmemset(name_C, 0, name_size+1); // clear buffer
+
    name_size = H5Fget_name(temp_id, name_C, name_size+1);
 
    // Check for failure again
diff --git a/c++/src/H5Location.cpp b/c++/src/H5Location.cpp
index b413a17..fdbfd61 100644
--- a/c++/src/H5Location.cpp
+++ b/c++/src/H5Location.cpp
@@ -32,6 +32,7 @@
 #include "H5File.h"
 #include "H5DataSet.h"
 #include "H5Attribute.h"
+#include "H5private.h"		// for HDmemset
 
 #ifndef H5_NO_NAMESPACE
 namespace H5 {
@@ -355,7 +356,7 @@ void H5Location::flush(H5F_scope_t scope) const
    herr_t ret_value = H5Fflush(getId(), scope);
    if( ret_value < 0 )
    {
-      throw Exception(inMemFunc("flush"), "H5Fflush failed");
+      throw LocationException(inMemFunc("flush"), "H5Fflush failed");
    }
 }
 
@@ -363,7 +364,7 @@ void H5Location::flush(H5F_scope_t scope) const
 // Function:	H5Location::getFileName
 ///\brief	Gets the name of the file, in which this HDF5 object belongs.
 ///\return	File name
-///\exception	H5::IdComponentException
+///\exception	H5::LocationException
 // Programmer	Binh-Minh Ribler - Jul, 2004
 //--------------------------------------------------------------------------
 H5std_string H5Location::getFileName() const
@@ -371,7 +372,7 @@ H5std_string H5Location::getFileName() const
    try {
       return(p_get_file_name());
    }
-   catch (IdComponentException E) {
+   catch (LocationException E) {
       throw FileIException(inMemFunc("getFileName"), E.getDetailMsg());
    }
 }
@@ -381,7 +382,7 @@ H5std_string H5Location::getFileName() const
 ///\brief	Sets or resets the comment for an object specified by its name.
 ///\param	name  - IN: Name of the object
 ///\param	comment - IN: New comment
-///\exception	H5::Exception
+///\exception	H5::LocationException
 ///\par	Description
 ///		If \a comment is an empty string or a null pointer, the comment
 ///		message is removed from the object.
@@ -400,7 +401,7 @@ void H5Location::setComment(const char* name, const char* comment) const
 {
    herr_t ret_value = H5Oset_comment_by_name(getId(), name, comment, H5P_DEFAULT);
    if( ret_value < 0 )
-      throw Exception(inMemFunc("setComment"), "H5Oset_comment_by_name failed");
+      throw LocationException(inMemFunc("setComment"), "H5Oset_comment_by_name failed");
 }
 
 //--------------------------------------------------------------------------
@@ -427,7 +428,7 @@ void H5Location::setComment(const char* comment) const
 {
    herr_t ret_value = H5Oset_comment_by_name(getId(), ".", comment, H5P_DEFAULT);
    if( ret_value < 0 )
-      throw Exception(inMemFunc("setComment"), "H5Oset_comment_by_name failed");
+      throw LocationException(inMemFunc("setComment"), "H5Oset_comment_by_name failed");
 }
 
 //--------------------------------------------------------------------------
@@ -446,7 +447,7 @@ void H5Location::setComment(const H5std_string& comment) const
 // Function:	H5Location::removeComment
 ///\brief	Removes the comment from an object specified by its name.
 ///\param	name  - IN: Name of the object
-///\exception	H5::Exception
+///\exception	H5::LocationException
 // Programmer	Binh-Minh Ribler - May 2005 (moved from CommonFG, Sep 2013)
 //	2007: QAK modified to use H5O APIs; however the first parameter is
 //		no longer just file or group, this function should be moved
@@ -457,7 +458,7 @@ void H5Location::removeComment(const char* name) const
 {
    herr_t ret_value = H5Oset_comment_by_name(getId(), name, NULL, H5P_DEFAULT);
    if( ret_value < 0 )
-      throw Exception(inMemFunc("removeComment"), "H5Oset_comment_by_name failed");
+      throw LocationException(inMemFunc("removeComment"), "H5Oset_comment_by_name failed");
 }
 
 //--------------------------------------------------------------------------
@@ -474,52 +475,87 @@ void H5Location::removeComment(const H5std_string& name) const
 
 //--------------------------------------------------------------------------
 // Function:	H5Location::getComment
-///\brief	Retrieves comment for the specified object and its comment's
-///		length.
-///\param	name  - IN: Name of the object
-///\param	bufsize - IN: Length of the comment to retrieve
+///\brief	Retrieves the comment for this location, returning its length.
+///\param	name     - IN: Name of the object
+///\param	buf_size - IN: Length of the comment to retrieve
+///\param	comment  - OUT: Retrieved comment
+///\return	Actual length of the comment
+///\exception	H5::LocationException
+///\par Description
+///		This function retrieves \a buf_size characters of the comment
+///		including the null terminator.  Thus, if the actual length
+///		of the comment is more than buf_size-1, the retrieved comment
+///		will be truncated to accommodate the null terminator.
+// Programmer	Binh-Minh Ribler - Mar 2014
+//--------------------------------------------------------------------------
+ssize_t H5Location::getComment(const char* name, const size_t buf_size, char* comment) const
+{
+    // H5Oget_comment_by_name will get buf_size chars of the comment including
+    // the null terminator
+    ssize_t comment_len;
+    comment_len = H5Oget_comment_by_name(getId(), name, comment, buf_size, H5P_DEFAULT);
+
+    // If H5Oget_comment_by_name returns a negative value, raise an exception
+    if (comment_len < 0)
+    {
+        throw LocationException("H5Location::getComment", "H5Oget_comment_by_name failed");
+    }
+
+    // Return the comment length, which might be different from buf_size
+    return(comment_len);
+}
+
+//--------------------------------------------------------------------------
+// Function:	H5Location::getComment
+///\brief	Returns the comment as \a string for this location,
+///		returning its length.
+///\param	name     - IN: Name of the object
+///\param	buf_size - IN: Length of the comment to retrieve, default to 0
 ///\return	Comment string
-///\exception	H5::Exception
+///\exception	H5::LocationException
 // Programmer	Binh-Minh Ribler - 2000 (moved from CommonFG, Sep 2013)
-//	2007: QAK modified to use H5O APIs; however the first parameter is
-//		no longer just file or group, this function should be moved
-//		to another class to accommodate attribute, dataset, and named
-//		datatype. - BMR
 //--------------------------------------------------------------------------
-H5std_string H5Location::getComment(const char* name, size_t bufsize) const
+H5std_string H5Location::getComment(const char* name, const size_t buf_size) const
 {
-   // bufsize is default to 256
-   // temporary variable
-   hid_t loc_id = getId();   // temporary variable
+    // Initialize string to "", so that if there is no comment, the returned
+    // string will be empty
+    H5std_string comment("");
 
-   // temporary C-string for the object's comment; bufsize already including
-   // null character
-   char* comment_C = new char[bufsize];
-   ssize_t ret_value = H5Oget_comment_by_name(loc_id, name, comment_C, bufsize, H5P_DEFAULT);
+    // Preliminary call to get the comment's length
+    ssize_t comment_len = H5Oget_comment_by_name(getId(), name, NULL, (size_t)0, H5P_DEFAULT);
 
-   // if the actual length of the comment is longer than bufsize and bufsize
-   // was the default value, i.e., not given by the user, then call
-   // H5Oget_comment_by_name again with the correct value.
-   // If the call to H5Oget_comment_by_name returned an error, skip this block
-   // and throw an exception below.
-   if (ret_value >= 0 && (size_t)ret_value > bufsize && bufsize == 256)
-   {
-	size_t new_size = ret_value;
-	delete []comment_C;
-	comment_C = new char[new_size];	// new_size including null terminator
-	ret_value = H5Oget_comment_by_name(loc_id, name, comment_C, new_size, H5P_DEFAULT);
-   }
+    // If H5Oget_comment_by_name returns a negative value, raise an exception
+    if (comment_len < 0)
+    {
+        throw LocationException("H5Location::getComment", "H5Oget_comment_by_name failed");
+    }
 
-   // if H5Oget_comment_by_name returns SUCCEED, return the string comment,
-   // otherwise, throw an exception
-   if (ret_value < 0) {
-       delete []comment_C;
-       throw Exception(inMemFunc("getComment"), "H5Oget_comment_by_name failed");
-   }
+    // If comment exists, calls C routine again to get it
+    else if (comment_len > 0)
+    {
+	size_t tmp_len = buf_size;
 
-   H5std_string comment = H5std_string(comment_C);
-   delete []comment_C;
-   return (comment);
+	// If buffer size is not provided, use comment length
+	if (tmp_len == 0)
+	    tmp_len = comment_len;
+
+	// Temporary buffer for char* comment
+	char* comment_C = new char[tmp_len+1];
+	HDmemset(comment_C, 0, tmp_len+1); // clear buffer
+
+	// Used overloaded function
+	ssize_t comment_len = getComment(name, tmp_len, comment_C);
+
+	// Convert the C comment to return
+	comment = comment_C;
+
+	// Clean up resource
+	delete []comment_C;
+    }
+    // Otherwise, keep comment intact
+
+    // Return the string comment
+    return(comment);
 }
 
 //--------------------------------------------------------------------------
@@ -529,9 +565,9 @@ H5std_string H5Location::getComment(const char* name, size_t bufsize) const
 ///		\c H5std_string for \a name.
 // Programmer	Binh-Minh Ribler - 2000 (moved from CommonFG, Sep 2013)
 //--------------------------------------------------------------------------
-H5std_string H5Location::getComment(const H5std_string& name, size_t bufsize) const
+H5std_string H5Location::getComment(const H5std_string& name, const size_t buf_size) const
 {
-   return(getComment(name.c_str(), bufsize));
+    return(getComment(name.c_str(), buf_size));
 }
 #ifndef DOXYGEN_SHOULD_SKIP_THIS
 
@@ -542,7 +578,7 @@ H5std_string H5Location::getComment(const H5std_string& name, size_t bufsize) co
 //		name - IN: Name of the object to be referenced
 //		dataspace - IN: Dataspace with selection
 //		ref_type - IN: Type of reference; default to \c H5R_DATASET_REGION
-// Exception	H5::IdComponentException
+// Exception	H5::ReferenceException
 // Programmer	Binh-Minh Ribler - May, 2004
 //--------------------------------------------------------------------------
 void H5Location::p_reference(void* ref, const char* name, hid_t space_id, H5R_type_t ref_type) const
diff --git a/c++/src/H5Location.h b/c++/src/H5Location.h
index bbe86fc..11dbf85 100644
--- a/c++/src/H5Location.h
+++ b/c++/src/H5Location.h
@@ -104,8 +104,9 @@ class H5_DLLCPP H5Location : public IdComponent {
 	void setComment(const H5std_string& comment) const;
 
 	// Retrieves comment for the HDF5 object specified by its name.
-	H5std_string getComment(const char* name, size_t bufsize=256) const;
-	H5std_string getComment(const H5std_string& name, size_t bufsize=256) const;
+	ssize_t getComment(const char* name, const size_t buf_size, char* comment) const;
+	H5std_string getComment(const char* name, size_t buf_size=0) const;
+	H5std_string getComment(const H5std_string& name, size_t buf_size=0) const;
 
 	// Removes the comment for the HDF5 object specified by its name.
 	void removeComment(const char* name) const;
diff --git a/c++/src/H5PropList.cpp b/c++/src/H5PropList.cpp
index 9476d46..a49995d 100644
--- a/c++/src/H5PropList.cpp
+++ b/c++/src/H5PropList.cpp
@@ -390,8 +390,13 @@ void PropList::getProperty(const char* name, void* value) const
 //--------------------------------------------------------------------------
 H5std_string PropList::getProperty(const char* name) const
 {
+   // Get property size first
    size_t size = getPropSize(name);
+
+   // Allocate buffer then get the property
    char* prop_strg_C = new char[size+1];  // temporary C-string for C API
+   HDmemset(prop_strg_C, 0, size+1); // clear buffer
+
    herr_t ret_value = H5Pget(id, name, prop_strg_C); // call C API
 
    // Throw exception if H5Pget returns failure
diff --git a/c++/test/dsets.cpp b/c++/test/dsets.cpp
index 811d8c7..b6922c2 100644
--- a/c++/test/dsets.cpp
+++ b/c++/test/dsets.cpp
@@ -120,6 +120,11 @@ test_create( H5File& file)
 	// way to open an existing dataset for accessing.
 	dataset = new DataSet (file.openDataSet (DSET_DEFAULT_NAME));
 
+	// Get and verify the comment from this dataset, using
+	// H5std_string getComment(const H5std_string& name, <buf_size=0, by default>)
+	H5std_string comment = file.getComment(DSET_DEFAULT_NAME);
+	verify_val(comment, "This is a dataset", "H5Location::getComment", __LINE__, __FILE__);
+
 	// Close the dataset when accessing is completed
 	delete dataset;
 
@@ -1067,6 +1072,12 @@ void test_dset()
 	nerrors += test_multiopen (file)<0	?1:0;
 	nerrors += test_types(file)<0       ?1:0;
 
+	// Get part of the comment, random length using
+	// ssize_t getComment(const char* name, const size_t buf_size, char* comment)
+	char* comment = new char[11];
+	ssize_t comment_len = file.getComment("emit diagnostics", 10, comment);
+	verify_val((const char*)comment, "Causes dia", "H5Location::getComment", __LINE__, __FILE__);
+
 	// Close group "emit diagnostics".
 	grp.close();
 
diff --git a/c++/test/trefer.cpp b/c++/test/trefer.cpp
index 36c2ee4..e7a28de 100644
--- a/c++/test/trefer.cpp
+++ b/c++/test/trefer.cpp
@@ -316,11 +316,13 @@ static void test_reference_obj(void)
 	// Dereference group object from the location where 'dataset' is located
 	group.dereference(dataset, &rbuf[2]);
 
-	// Get group's comment
+	// Get group's comment using
+	// H5std_string getComment(const char* name, <buf_size=0 by default>)
 	H5std_string read_comment1 = group.getComment(".", 10);
 	verify_val(read_comment1.c_str(), write_comment, "Group::getComment",__LINE__,__FILE__);
 
-	// Test that getComment handles failures gracefully
+	// Test that getComment handles failures gracefully, using
+	// H5std_string getComment(const char* name, <buf_size=0 by default>)
 	try {
 	    H5std_string read_comment_tmp = group.getComment(NULL);
 	}