var: do not print usage() with a correct invocation

Before, git-var could print usage() even if the command was invoked
correctly with a variable defined in git_vars -- provided that its
read() function returned NULL.

Now, we only print usage() only if it was called with a logical
variable that wasn't defined -- regardless of read().

Since we now know the variable is valid when we call read_var(), we
can avoid printing usage() here (and exiting with code 129) and
instead exit quietly with code 1. While exiting with a different code
can be a breaking change, it's far better than changing the exit
status more generally from 'failure' to 'success'.

Signed-off-by: Sean Allred <allred.sean@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-var.txt b/Documentation/git-var.txt
index 6aa521fab2383e5e0d4aaf39d03f695ea53940d3..0ab5bfa7d725749543b61568966762a37bce4535 100644 (file)
--- a/Documentation/git-var.txt
+++ b/Documentation/git-var.txt
@@ -13,7 +13,8 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-Prints a Git logical variable.
+Prints a Git logical variable. Exits with code 1 if the variable has
+no value.
 
 OPTIONS
 -------

diff --git a/builtin/var.c b/builtin/var.c
index 491db2742926dbd6fd08f681817821addcfafab7..5cbe32ec89096d12c792c50b4831ab69563ac3de 100644 (file)
--- a/builtin/var.c
+++ b/builtin/var.c
@@ -56,18 +56,15 @@ static void list_vars(void)
                        printf("%s=%s\n", ptr->name, val);
 }
 
-static const char *read_var(const char *var)
+static const struct git_var *get_git_var(const char *var)
 {
        struct git_var *ptr;
-       const char *val;
-       val = NULL;
        for (ptr = git_vars; ptr->read; ptr++) {
                if (strcmp(var, ptr->name) == 0) {
-                       val = ptr->read(IDENT_STRICT);
-                       break;
+                       return ptr;
                }
        }
-       return val;
+       return NULL;
 }
 
 static int show_config(const char *var, const char *value, void *cb)
@@ -81,7 +78,9 @@ static int show_config(const char *var, const char *value, void *cb)
 
 int cmd_var(int argc, const char **argv, const char *prefix)
 {
-       const char *val = NULL;
+       const struct git_var *git_var;
+       const char *val;
+
        if (argc != 2)
                usage(var_usage);
 
@@ -91,10 +90,15 @@ int cmd_var(int argc, const char **argv, const char *prefix)
                return 0;
        }
        git_config(git_default_config, NULL);
-       val = read_var(argv[1]);
-       if (!val)
+
+       git_var = get_git_var(argv[1]);
+       if (!git_var)
                usage(var_usage);
 
+       val = git_var->read(IDENT_STRICT);
+       if (!val)
+               return 1;
+
        printf("%s\n", val);
 
        return 0;