[PATCH 1/2] system_path: move RUNTIME_PREFIX to a sub-function

[Jeff King <peff@peff.net>]

The system_path() function has an #ifdef in the middle of
it. Let's move the conditional logic into a sub-function.
This isolates it more, which will make it easier to change
and add to.

Signed-off-by: Jeff King <peff@peff.net>
---
I find the diff hard to read because it shows the opposite of what I did
(moving the big block to its own function, rather than moving the little
bits to a new copy of the function).

 exec_cmd.c | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/exec_cmd.c b/exec_cmd.c
index fb94aeba9c..61092e9715 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -7,19 +7,12 @@
 static const char *argv_exec_path;
 static const char *argv0_path;
 
-char *system_path(const char *path)
-{
 #ifdef RUNTIME_PREFIX
-	static const char *prefix;
-#else
-	static const char *prefix = PREFIX;
-#endif
-	struct strbuf d = STRBUF_INIT;
 
-	if (is_absolute_path(path))
-		return xstrdup(path);
+static const char *system_prefix(void)
+{
+	static const char *prefix;
 
-#ifdef RUNTIME_PREFIX
 	assert(argv0_path);
 	assert(is_absolute_path(argv0_path));
 
@@ -32,9 +25,25 @@ char *system_path(const char *path)
 				"but prefix computation failed.  "
 				"Using static fallback '%s'.\n", prefix);
 	}
-#endif
+	return prefix;
+}
+#else
+
+static const char *system_prefix(void)
+{
+	return PREFIX;
+}
+
+#endif /* RUNTIME_PREFIX */
+
+char *system_path(const char *path)
+{
+	struct strbuf d = STRBUF_INIT;
+
+	if (is_absolute_path(path))
+		return xstrdup(path);
 
-	strbuf_addf(&d, "%s/%s", prefix, path);
+	strbuf_addf(&d, "%s/%s", system_prefix(), path);
 	return strbuf_detach(&d, NULL);
 }
 
-- 
2.14.1.757.g8fad538cea