Pacify gcc 11.1.1 -Wanalyzer-null-argument

* lib-src/etags.c (regexp): Omit member force_explicit_name,
since it’s always true.  All uses removed.  This lets us
remove calls to strlen (name) where GCC isn’t smart enough
to deduce that name must be nonnull.
* lib-src/movemail.c (main): Fix bug that could cause
link (tempname, NULL) to be called.
* src/emacs.c (argmatch): Break check into two ‘if’s,
since GCC doesn’t seem to be smart enough to check the single ‘if’.
* src/gtkutil.c (xg_update_menu_item): Fix bug where strcmp
could be given a NULL arg.
* src/xfont.c (xfont_list_family): Use nonnull value for dummy
initial value.

2 files changed, 24 insertions, 39 deletions

diff --git a/lib-src/etags.c b/lib-src/etags.c
index c39c93db336..88b49f803e9 100644
--- a/lib-src/etags.c
+++ b/lib-src/etags.c
@@ -340,7 +340,6 @@ typedef struct regexp
   struct re_pattern_buffer *pat; /* the compiled pattern */
   struct re_registers regs;     /* re registers */
   bool error_signaled;          /* already signaled for this regexp */
-  bool force_explicit_name;     /* do not allow implicit tag name */
   bool ignore_case;             /* ignore case when matching */
   bool multi_line;              /* do a multi-line match on the whole file */
 } regexp;
@@ -6910,7 +6909,6 @@ add_regex (char *regexp_pattern, language *lang)
   struct re_pattern_buffer *patbuf;
   regexp *rp;
   bool
-    force_explicit_name = true, /* do not use implicit tag names */
     ignore_case = false,        /* case is significant */
     multi_line = false,         /* matches are done one line at a time */
     single_line = false;        /* dot does not match newline */
@@ -6949,7 +6947,8 @@ add_regex (char *regexp_pattern, language *lang)
       case 'N':
         if (modifiers == name)
           error ("forcing explicit tag name but no name, ignoring");
-        force_explicit_name = true;
+        /* This option has no effect and is present only for backward
+           compatibility.  */
         break;
       case 'i':
         ignore_case = true;
@@ -7004,7 +7003,6 @@ add_regex (char *regexp_pattern, language *lang)
   p_head->pat = patbuf;
   p_head->name = savestr (name);
   p_head->error_signaled = false;
-  p_head->force_explicit_name = force_explicit_name;
   p_head->ignore_case = ignore_case;
   p_head->multi_line = multi_line;
 }
@@ -7144,20 +7142,15 @@ regex_tag_multiline (void)
                 name = NULL;
               else /* make a named tag */
                 name = substitute (buffer, rp->name, &rp->regs);
-              if (rp->force_explicit_name)
-                {
-                  /* Force explicit tag name, if a name is there. */
-                  pfnote (name, true, buffer + linecharno,
-                          charno - linecharno + 1, lineno, linecharno);
-
-                  if (debug)
-                    fprintf (stderr, "%s on %s:%"PRIdMAX": %s\n",
-                             name ? name : "(unnamed)", curfdp->taggedfname,
-                             lineno, buffer + linecharno);
-                }
-              else
-                make_tag (name, strlen (name), true, buffer + linecharno,
-                          charno - linecharno + 1, lineno, linecharno);
+
+              /* Force explicit tag name, if a name is there. */
+              pfnote (name, true, buffer + linecharno,
+                      charno - linecharno + 1, lineno, linecharno);
+
+              if (debug)
+                fprintf (stderr, "%s on %s:%"PRIdMAX": %s\n",
+                         name ? name : "(unnamed)", curfdp->taggedfname,
+                         lineno, buffer + linecharno);
               break;
             }
         }
@@ -7471,18 +7464,14 @@ readline (linebuffer *lbp, FILE *stream)
                 name = NULL;
               else /* make a named tag */
                 name = substitute (lbp->buffer, rp->name, &rp->regs);
-              if (rp->force_explicit_name)
-                {
-                  /* Force explicit tag name, if a name is there. */
-                  pfnote (name, true, lbp->buffer, match, lineno, linecharno);
-                  if (debug)
-                    fprintf (stderr, "%s on %s:%"PRIdMAX": %s\n",
-                             name ? name : "(unnamed)", curfdp->taggedfname,
-                             lineno, lbp->buffer);
-                }
-              else
-                make_tag (name, strlen (name), true,
-                          lbp->buffer, match, lineno, linecharno);
+
+              /* Force explicit tag name, if a name is there. */
+              pfnote (name, true, lbp->buffer, match, lineno, linecharno);
+
+              if (debug)
+                fprintf (stderr, "%s on %s:%"PRIdMAX": %s\n",
+                         name ? name : "(unnamed)", curfdp->taggedfname,
+                         lineno, lbp->buffer);
               break;
             }
         }
diff --git a/lib-src/movemail.c b/lib-src/movemail.c
index cfdebccb8d0..e683da179df 100644
--- a/lib-src/movemail.c
+++ b/lib-src/movemail.c
@@ -270,6 +270,7 @@ main (int argc, char **argv)
          You might also wish to verify that your system is one which
          uses lock files for this purpose.  Some systems use other methods.  */
 
+      bool lockname_unlinked = false;
       inname_len = strlen (inname);
       lockname = xmalloc (inname_len + sizeof ".lock");
       strcpy (lockname, inname);
@@ -312,15 +313,10 @@ main (int argc, char **argv)
              Five minutes should be good enough to cope with crashes
              and wedgitude, and long enough to avoid being fooled
              by time differences between machines.  */
-          if (stat (lockname, &st) >= 0)
-            {
-              time_t now = time (0);
-              if (st.st_ctime < now - 300)
-                {
-                  unlink (lockname);
-                  lockname = 0;
-                }
-            }
+          if (!lockname_unlinked
+              && stat (lockname, &st) == 0
+              && st.st_ctime < time (0) - 300)
+            lockname_unlinked = unlink (lockname) == 0 || errno == ENOENT;
         }
 
       delete_lockname = lockname;