--enable-gcc-warnings now uses -Wjump-misses-init

When configuring with --enable-gcc-warnings, also enable
-Wjump-misses-init, as it’s confusing to use a goto to skip over
an initialization.  Fix the few places in the code that run afoul
of this warning.
* configure.ac (WERROR_CFLAGS): Add -Wjump-misses-init.
* src/doc.c (Fsubstitute_command_keys):
* src/image.c (svg_load_image):
* src/regex.c (re_match_2_internal):
* src/xdisp.c (redisplay_internal, redisplay_window):
Don’t jump over initialization.

1 files changed, 17 insertions, 16 deletions

diff --git a/src/regex.c b/src/regex.c
index 164eb4612ae..d5c58aeaf8b 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -5140,8 +5140,6 @@ re_match_2_internal (struct re_pattern_buffer *bufp, const_re_char *string1,
 
       if (p == pend)
         {
-          ptrdiff_t dcnt;
-
           /* End of pattern means we might have succeeded.  */
           DEBUG_PRINT ("end of pattern ... ");
 
@@ -5149,19 +5147,22 @@ re_match_2_internal (struct re_pattern_buffer *bufp, const_re_char *string1,
              longest match, try backtracking.  */
           if (d != end_match_2)
             {
-              /* 1 if this match ends in the same string (string1 or string2)
-                 as the best previous match.  */
-              boolean same_str_p = (FIRST_STRING_P (match_end)
-                                    == FIRST_STRING_P (d));
-              /* 1 if this match is the best seen so far.  */
-              boolean best_match_p;
-
-              /* AIX compiler got confused when this was combined
-                 with the previous declaration.  */
-              if (same_str_p)
-                best_match_p = d > match_end;
-              else
-                best_match_p = !FIRST_STRING_P (d);
+              /* True if this match is the best seen so far.  */
+              bool best_match_p;
+
+              {
+                /* True if this match ends in the same string (string1
+                   or string2) as the best previous match.  */
+                bool same_str_p = (FIRST_STRING_P (match_end)
+                                   == FIRST_STRING_P (d));
+
+                /* AIX compiler got confused when this was combined
+                   with the previous declaration.  */
+                if (same_str_p)
+                  best_match_p = d > match_end;
+                else
+                  best_match_p = !FIRST_STRING_P (d);
+              }
 
               DEBUG_PRINT ("backtracking.\n");
 
@@ -5290,7 +5291,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp, const_re_char *string1,
                        nfailure_points_pushed - nfailure_points_popped);
           DEBUG_PRINT ("%u registers pushed.\n", num_regs_pushed);
 
-          dcnt = POINTER_TO_OFFSET (d) - pos;
+          ptrdiff_t dcnt = POINTER_TO_OFFSET (d) - pos;
 
           DEBUG_PRINT ("Returning %td from re_match_2.\n", dcnt);