cutils: Provide strchrnul

strchrnul is a GNU extension and thus unavailable on a number of targets.
In the review for a commit removing strchrnul from 9p, I was asked to
create a qemu_strchrnul helper to factor out this functionality.
Do so, and use it in a number of other places in the code base that inlined
the replacement pattern in a place where strchrnul could be used.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>

3 files changed, 18 insertions, 9 deletions

diff --git a/util/cutils.c b/util/cutils.c
index 0de69e6..9205e09 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -545,6 +545,21 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base,
 }
 
 /**
+ * Searches for the first occurrence of 'c' in 's', and returns a pointer
+ * to the trailing null byte if none was found.
+ */
+#ifndef HAVE_STRCHRNUL
+const char *qemu_strchrnul(const char *s, int c)
+{
+    const char *e = strchr(s, c);
+    if (!e) {
+        e = s + strlen(s);
+    }
+    return e;
+}
+#endif
+
+/**
  * parse_uint:
  *
  * @s: String to parse
diff --git a/util/qemu-option.c b/util/qemu-option.c
index ba44a08..19761e3 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -77,11 +77,7 @@ const char *get_opt_value(const char *p, char **value)
 
     *value = NULL;
     while (1) {
-        offset = strchr(p, ',');
-        if (!offset) {
-            offset = p + strlen(p);
-        }
-
+        offset = qemu_strchrnul(p, ',');
         length = offset - p;
         if (*offset != '\0' && *(offset + 1) == ',') {
             length++;
diff --git a/util/uri.c b/util/uri.c
index 8624a7a..8bdef84 100644
--- a/util/uri.c
+++ b/util/uri.c
@@ -52,6 +52,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 
 #include "qemu/uri.h"
 
@@ -2266,10 +2267,7 @@ struct QueryParams *query_params_parse(const char *query)
         /* Find the next separator, or end of the string. */
         end = strchr(query, '&');
         if (!end) {
-            end = strchr(query, ';');
-        }
-        if (!end) {
-            end = query + strlen(query);
+            end = qemu_strchrnul(query, ';');
         }
 
         /* Find the first '=' character between here and end. */