util: add greedy_realloc0()

Compared to greedy_realloc(), this sets all newly allocated memory to 0.
As the old variant has been used a lot for string-handling, we avoid
changing it as clearing memory is not needed there.

2 files changed, 17 insertions, 0 deletions

diff --git a/src/shared/util.c b/src/shared/util.c
index 305a6c2fb..b4ed2c407 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -5806,6 +5806,20 @@ void* greedy_realloc(void **p, size_t *allocated, size_t need) {
         return q;
 }
 
+void* greedy_realloc0(void **p, size_t *allocated, size_t need) {
+        size_t prev = *allocated;
+        uint8_t *q;
+
+        q = greedy_realloc(p, allocated, need);
+        if (!q)
+                return NULL;
+
+        if (*allocated > prev)
+                memset(&q[prev], 0, *allocated - prev);
+
+        return q;
+}
+
 bool id128_is_valid(const char *s) {
         size_t i, l;
 
diff --git a/src/shared/util.h b/src/shared/util.h
index 1662bd445..504f63a28 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -669,8 +669,11 @@ char *strextend(char **x, ...) _sentinel_;
 char *strrep(const char *s, unsigned n);
 
 void* greedy_realloc(void **p, size_t *allocated, size_t need);
+void* greedy_realloc0(void **p, size_t *allocated, size_t need);
 #define GREEDY_REALLOC(array, allocated, need) \
         greedy_realloc((void**) &(array), &(allocated), sizeof((array)[0]) * (need))
+#define GREEDY_REALLOC0(array, allocated, need) \
+        greedy_realloc0((void**) &(array), &(allocated), sizeof((array)[0]) * (need))
 
 static inline void _reset_errno_(int *saved_errno) {
         errno = *saved_errno;