README.Coding: Add hint for if-statments

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Mon Jan 19 13:25:12 CET 2015 on sn-devel-104

1 files changed, 27 insertions, 19 deletions

diff --git a/README.Coding b/README.Coding
index 0bbba9fc45..f19399e7f2 100644
--- a/README.Coding
+++ b/README.Coding
@@ -298,25 +298,6 @@ Good Examples:
 	}
 
 
-Checking Pointer Values
------------------------
-
-When invoking functions that return pointer values, either of the following
-are acceptable. Use your best judgement and choose the more readable option.
-Remember that many other persons will review it:
-
-	if ((x = malloc(sizeof(short)*10)) == NULL ) {
-		fprintf(stderr, "Unable to alloc memory!\n");
-	}
-
-or:
-
-	x = malloc(sizeof(short)*10);
-	if (!x) {
-		fprintf(stderr, "Unable to alloc memory!\n");
-	}
-
-
 Primitive Data Types
 --------------------
 
@@ -364,6 +345,33 @@ Bad Example:
 	ret = some_function_my_name(get_some_name());
 	...
 
+Please try to avoid passing function return values to if- or
+while-conditions. The reason for this is better handling of code under a
+debugger.
+
+Good example:
+
+	x = malloc(sizeof(short)*10);
+	if (!x) {
+		fprintf(stderr, "Unable to alloc memory!\n");
+	}
+
+Bad example:
+
+	if ((x = malloc(sizeof(short)*10)) == NULL ) {
+		fprintf(stderr, "Unable to alloc memory!\n");
+	}
+
+There are exceptions to this rule. One example is walking a data structure in
+an iterator style:
+
+	while ((opt = poptGetNextOpt(pc)) != -1) {
+		   ... do something with opt ...
+	}
+
+But in general, please try to avoid this pattern.
+
+
 Control-Flow changing macros
 ----------------------------