[PATCH] merge-recursive: check GIT_MERGE_VERBOSITY only once

[Andrey Okoshkin]

Add check of 'GIT_MERGE_VERBOSITY' environment variable only once in
init_merge_options().
Consequential call of getenv() may return NULL pointer and strtol() crashes.
However the stored pointer to the obtained getenv() result may be invalidated
by some other getenv() call from another thread as getenv() is not thread-safe.

Signed-off-by: Andrey Okoshkin <a.okosh...@samsung.com>
---
 merge-recursive.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/merge-recursive.c b/merge-recursive.c
index 1494ffdb8..eaac98145 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -2163,6 +2163,7 @@ static void merge_recursive_config(struct merge_options 
*o)
 
 void init_merge_options(struct merge_options *o)
 {
+       const char *merge_verbosity = getenv("GIT_MERGE_VERBOSITY");
        memset(o, 0, sizeof(struct merge_options));
        o->verbosity = 2;
        o->buffer_output = 1;
@@ -2171,9 +2172,8 @@ void init_merge_options(struct merge_options *o)
        o->renormalize = 0;
        o->detect_rename = 1;
        merge_recursive_config(o);
-       if (getenv("GIT_MERGE_VERBOSITY"))
-               o->verbosity =
-                       strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
+       if (merge_verbosity)
+               o->verbosity = strtol(merge_verbosity, NULL, 10);
        if (o->verbosity >= 5)
                o->buffer_output = 0;
        strbuf_init(&o->obuf, 0);
-- 
2.14.3