cmd/run: Fix fork mode when given exclude patterns

If a user requests exactly one test on the command line, then Crucible
automatically disables forking to ease debugging. The Bug: Crucible
incorrectly disabled forking when the user gave crucible-run exactly one
test pattern, and the pattern was an exclude pattern.

1 files changed, 19 insertions, 1 deletions

diff --git a/src/cmd/run.c b/src/cmd/run.c
index 0d4dda6..510c555 100644
--- a/src/cmd/run.c
+++ b/src/cmd/run.c
@@ -174,10 +174,28 @@ done_getopt:
     }
 }
 
+// Do the command line args specify exactly one test?
 static bool
 one_test(void)
 {
-    return test_patterns.len == 1 && !strstr(test_patterns.data[0], "*");
+    if (test_patterns.len > 1)
+        return false;
+
+    const char *first_pattern = test_patterns.data[0];
+
+    if (first_pattern[0] == '!') {
+        // From the crucible-run(1) man page:
+        //
+        //      If the first given pattern is an exclude pattern, then Crucible
+        //      inserts an implied "*" as the first pattern.
+        return false;
+    }
+
+    // A glob may match multiple tests.
+    if (strstr(test_patterns.data[0], "*"))
+        return false;
+
+    return true;
 }
 
 static uint32_t