BUG/MINOR: compression: Missing calloc return value check in comp_append_type/algo

A memory allocation failure happening in comp_append_type or
comp_append_algo called while parsing compression options would have
resulted in a crash. These functions are only called during
configuration parsing.

It was raised in GitHub issue #1233.
It could be backported to all stable branches.

(cherry picked from commit 6443bcc2e1f2e1e11af76ef460d8241f06223de8)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit a3a8d50d992ab145e5c353cc36e8a787d3aead57)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 46bd5dca638832fea6ce529caebf07cb034b9e3b)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 2765a6473cb1f98a424b7c19db4b8e52c8ed4350)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/compression.c b/src/compression.c
index 413a9d8..88ca0bc 100644
--- a/src/compression.c
+++ b/src/compression.c
@@ -112,12 +112,15 @@
 
 /*
  * Add a content-type in the configuration
+ * Returns 0 in case of success, 1 in case of allocation failure.
  */
 int comp_append_type(struct comp *comp, const char *type)
 {
 	struct comp_type *comp_type;
 
 	comp_type = calloc(1, sizeof(*comp_type));
+	if (!comp_type)
+		return 1;
 	comp_type->name_len = strlen(type);
 	comp_type->name = strdup(type);
 	comp_type->next = comp->types;
@@ -127,6 +130,8 @@
 
 /*
  * Add an algorithm in the configuration
+ * Returns 0 in case of success, -1 if the <algo> is unmanaged, 1 in case of
+ * allocation failure.
  */
 int comp_append_algo(struct comp *comp, const char *algo)
 {
@@ -136,6 +141,8 @@
 	for (i = 0; comp_algos[i].cfg_name; i++) {
 		if (!strcmp(algo, comp_algos[i].cfg_name)) {
 			comp_algo = calloc(1, sizeof(*comp_algo));
+			if (!comp_algo)
+				return 1;
 			memmove(comp_algo, &comp_algos[i], sizeof(struct comp_algo));
 			comp_algo->next = comp->algos;
 			comp->algos = comp_algo;