git_exec_path: avoid Coverity warning about unfree()d result

dscho · gitster · commit c9bb5d101ca6 · 2017-01-08T17:21:32.000-08:00
Technically, it is correct that git_exec_path() returns a possibly
malloc()ed string returned from system_path(), and it is sometimes
not allocated.  Cache the result in a static variable and make sure
that we call system_path() only once, which plugs a potential leak.

Signed-off-by: Johannes Schindelin &lt;johannes.schindelin@gmx.de&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/exec_cmd.c b/exec_cmd.c
@@ -69,6 +69,7 @@ void git_set_argv_exec_path(const char *exec_path)
 const char *git_exec_path(void)
 {
 	const char *env;
+	static char *system_exec_path;
 
 	if (argv_exec_path)
 		return argv_exec_path;
@@ -78,7 +79,9 @@ const char *git_exec_path(void)
 		return env;
 	}
 
-	return system_path(GIT_EXEC_PATH);
+	if (!system_exec_path)
+		system_exec_path = system_path(GIT_EXEC_PATH);
+	return system_exec_path;
 }
 
 static void add_path(struct strbuf *out, const char *path)

Original file line number	Diff line number	Diff line change
`@@ -69,6 +69,7 @@ void git_set_argv_exec_path(const char *exec_path)`
`69`	`69`	`const char *git_exec_path(void)`
`70`	`70`	`{`
`71`	`71`	`const char *env;`
	`72`	`+ static char *system_exec_path;`
`72`	`73`
`73`	`74`	`if (argv_exec_path)`
`74`	`75`	`return argv_exec_path;`
`@@ -78,7 +79,9 @@ const char *git_exec_path(void)`
`78`	`79`	`return env;`
`79`	`80`	`}`
`80`	`81`
`81`		`- return system_path(GIT_EXEC_PATH);`
	`82`	`+ if (!system_exec_path)`
	`83`	`+ system_exec_path = system_path(GIT_EXEC_PATH);`
	`84`	`+ return system_exec_path;`
`82`	`85`	`}`
`83`	`86`
`84`	`87`	`static void add_path(struct strbuf out, const char path)`