remove unnecessary check before QSORT

Add a semantic patch for removing checks similar to the one that QSORT
already does internally and apply it to the code base.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fmt-merge-msg.c

@@ -314,12 +314,10 @@ static void add_people_info(struct strbuf *out,
 			    struct string_list *authors,
 			    struct string_list *committers)
 {
-	if (authors->nr)
-		QSORT(authors->items, authors->nr,
-		      cmp_string_list_util_as_integral);
-	if (committers->nr)
-		QSORT(committers->items, committers->nr,
-		      cmp_string_list_util_as_integral);
+	QSORT(authors->items, authors->nr,
+	      cmp_string_list_util_as_integral);
+	QSORT(committers->items, committers->nr,
+	      cmp_string_list_util_as_integral);
 
 	credit_people(out, authors, 'a');
 	credit_people(out, committers, 'c');

contrib/coccinelle/qsort.cocci

@@ -17,3 +17,21 @@ expression nmemb, compar;
 @@
 - qsort(base, nmemb, sizeof(T), compar);
 + QSORT(base, nmemb, compar);
+
+@@
+expression base, nmemb, compar;
+@@
+- if (nmemb)
+    QSORT(base, nmemb, compar);
+
+@@
+expression base, nmemb, compar;
+@@
+- if (nmemb > 0)
+    QSORT(base, nmemb, compar);
+
+@@
+expression base, nmemb, compar;
+@@
+- if (nmemb > 1)
+    QSORT(base, nmemb, compar);

sh-i18n--envsubst.c

@@ -230,8 +230,7 @@ cmp_string (const void *pstr1, const void *pstr2)
 static inline void
 string_list_sort (string_list_ty *slp)
 {
-  if (slp->nitems > 0)
-    QSORT(slp->item, slp->nitems, cmp_string);
+  QSORT(slp->item, slp->nitems, cmp_string);
 }
 
 /* Test whether a sorted string list contains a given string.  */