[PATCH] gdb/debuginfod: Whitespace-only URL should disable debuginfod

[Aaron Merey <amerey@redhat.com>]

Currently debuginfod is disabled when the string of server URLs
is unset or set to be the empty string (via the $DEBUGINFOD_URLS
environment variable or the 'set debuginfod urls' gdb command).

Extend this functionality so that a whitespace-only URL also disables
debuginfod.

Modify a testcase to verify that a whitespace-only URL disables
debuginfod.
---
 gdb/debuginfod-support.c                        |  6 +++---
 .../gdb.debuginfod/fetch_src_and_symbols.exp    | 17 +++++++++++++----
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/gdb/debuginfod-support.c b/gdb/debuginfod-support.c
index 4ce2e786b6a..f47ed515e28 100644
--- a/gdb/debuginfod-support.c
+++ b/gdb/debuginfod-support.c
@@ -173,10 +173,10 @@ get_debuginfod_client ()
 static bool
 debuginfod_is_enabled ()
 {
-  const char *urls = getenv (DEBUGINFOD_URLS_ENV_VAR);
+  std::string urls = getenv (DEBUGINFOD_URLS_ENV_VAR) ?: "";
 
-  if (urls == nullptr || urls[0] == '\0'
-      || debuginfod_enabled == debuginfod_off)
+  if (debuginfod_enabled == debuginfod_off
+      || urls.find_first_not_of (' ') == std::string::npos)
     return false;
 
   if (debuginfod_enabled == debuginfod_ask)
diff --git a/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp b/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp
index bd90bcd0cfe..8b1618c242b 100644
--- a/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp
+++ b/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp
@@ -307,9 +307,10 @@ proc local_url { } {
     # Empty URLS disables Debuginfod.
     setenv DEBUGINFOD_URLS ""
     clean_restart
+    set file_cmd "with confirm off -- file $binfile"
     # Disable confirmation to avoid having to deal with a query.  See
     # test_urls.
-    gdb_test_multiple "with confirm off -- file $binfile" "notice empty URL" {
+    gdb_test_multiple $file_cmd "notice empty URL" {
 	-re -wrap "This GDB supports auto-downloading.*" {
 	    fail $gdb_test_name
 	}
@@ -318,9 +319,17 @@ proc local_url { } {
 	}
     }
 
-    test_urls "   " \
-        "" \
-        "notice whitespace URL"
+    # Whitespace-only URLS disables Debuginfod.
+    setenv DEBUGINFOD_URLS "    "
+    clean_restart
+    gdb_test_multiple $file_cmd "notice whitespace URL" {
+	-re -wrap "This GDB supports auto-downloading.*" {
+	    fail $gdb_test_name
+	}
+	-re -wrap "" {
+	    pass $gdb_test_name
+	}
+    }
 
     set url "http://127.0.0.1:$port"
 
-- 
2.35.1