Rewrite various initializations for the benefit of various compilers
Mark the initialization of `png_signature[]` as static const inside the
function `png_sig_cmp`. This might be helpful to optimizing compilers.
Initialize the arrays `number_buf[]`, `digits[]` and `buffer[]` inside
the functions `png_convert_to_rfc1123_buffer`, `png_ascii_from_fixed`,
`png_warning_parameter_unsigned` and `png_warning_parameter_signed`.
Although these initializations are redundant, compilers such as gcc-13
fail to see the redundancy.
diff --git a/png.c b/png.c
index 1bcf042..9cc560e 100644
--- a/png.c
+++ b/png.c
@@ -53,7 +53,7 @@
int PNGAPI
png_sig_cmp(png_const_bytep sig, size_t start, size_t num_to_check)
{
- png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+ static const png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
if (num_to_check > 8)
num_to_check = 8;
@@ -731,7 +731,7 @@
{
size_t pos = 0;
- char number_buf[5]; /* enough for a four-digit year */
+ char number_buf[5] = {0, 0, 0, 0, 0}; /* enough for a four-digit year */
# define APPEND_STRING(string) pos = png_safecat(out, 29, pos, (string))
# define APPEND_NUMBER(format, value)\
@@ -3218,7 +3218,7 @@
if (num <= 0x80000000) /* else overflowed */
{
unsigned int ndigits = 0, first = 16 /* flag value */;
- char digits[10];
+ char digits[10] = {0};
while (num)
{
diff --git a/pngerror.c b/pngerror.c
index ec3a709..53e79ba 100644
--- a/pngerror.c
+++ b/pngerror.c
@@ -255,7 +255,7 @@
png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
png_alloc_size_t value)
{
- char buffer[PNG_NUMBER_BUFFER_SIZE];
+ char buffer[PNG_NUMBER_BUFFER_SIZE] = {0};
png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
}
@@ -265,7 +265,7 @@
{
png_alloc_size_t u;
png_charp str;
- char buffer[PNG_NUMBER_BUFFER_SIZE];
+ char buffer[PNG_NUMBER_BUFFER_SIZE] = {0};
/* Avoid overflow by doing the negate in a png_alloc_size_t: */
u = (png_alloc_size_t)value;
