tidy-up: miscellaneous

- INSTALL-CMAKE.md: add missing periods, text fixes.
- md4, md5: sync variables names.
- curl_trc: sync an argument type.
- docs/examples: sync debug/trace function copies, constify, tidy-ups.
- replace commented code with `#if 0`.
- drop redundant parenthesis (macro values, `return`, around single
  variables, function calls).
- fix indentation, apply clang-format in places.

Closes #20481

tests/libtest/cli_hx_download.c

@@ -404,7 +404,9 @@ static CURLcode test_cli_hx_download(const char *URL)
   curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE);
   curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_DNS);
   curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_SSL_SESSION);
-  /* curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT); */
+#if 0
+  curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT);
+#endif
   curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_PSL);
   curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_HSTS);
 

tests/libtest/cli_upload_pausing.c

@@ -65,7 +65,9 @@ static int progress_callback(void *clientp,
   {
     CURL *curl = (CURL *)clientp;
     curl_easy_pause(curl, CURLPAUSE_CONT);
-    /* curl_easy_pause(curl, CURLPAUSE_RECV_CONT); */
+#if 0
+    curl_easy_pause(curl, CURLPAUSE_RECV_CONT);
+#endif
   }
 #endif
   return 0;

tests/libtest/lib1509.c

@@ -43,10 +43,10 @@ static size_t WriteHeader(char *ptr, size_t size, size_t nmemb, void *stream)
 
 static CURLcode test_lib1509(const char *URL)
 {
-  long headerSize;
-  CURLcode code;
   CURL *curl = NULL;
+  CURLcode code;
   CURLcode result = CURLE_OK;
+  long headerSize;
 
   global_init(CURL_GLOBAL_ALL);
 

tests/libtest/lib1517.c

@@ -95,8 +95,10 @@ static CURLcode test_lib1517(const char *URL)
   /* include headers in the output */
   test_setopt(curl, CURLOPT_HEADER, 1L);
 
+#if 0
   /* detect HTTP error codes >= 400 */
-  /* test_setopt(curl, CURLOPT_FAILONERROR, 1L); */
+  test_setopt(curl, CURLOPT_FAILONERROR, 1L);
+#endif
 
   /* Perform the request, result will get the return code */
   result = curl_easy_perform(curl);

tests/libtest/lib1556.c

@@ -42,8 +42,8 @@ static size_t header(char *ptr, size_t size, size_t nmemb, void *stream)
 
 static CURLcode test_lib1556(const char *URL)
 {
-  CURLcode code;
   CURL *curl = NULL;
+  CURLcode code;
   CURLcode result = CURLE_OK;
   struct headerinfo info = { 0 };
 

tests/libtest/lib518.c

@@ -29,7 +29,7 @@
 #error "this test requires FD_SETSIZE"
 #endif
 
-#define T518_SAFETY_MARGIN (16)
+#define T518_SAFETY_MARGIN 16
 
 #define NUM_OPEN   (FD_SETSIZE + 10)
 #define NUM_NEEDED (NUM_OPEN + T518_SAFETY_MARGIN)

tests/libtest/lib537.c

@@ -29,7 +29,7 @@
 #error "this test requires FD_SETSIZE"
 #endif
 
-#define T537_SAFETY_MARGIN (11)
+#define T537_SAFETY_MARGIN 11
 
 #if defined(_WIN32) || defined(MSDOS)
 #define DEV_NULL "NUL"

tests/libtest/lib571.c

@@ -69,14 +69,18 @@ static size_t rtp_write(char *data, size_t size, size_t nmemb, void *stream)
     if(message_size - i > RTP_DATA_SIZE) {
       if(memcmp(RTP_DATA, data + i, RTP_DATA_SIZE) != 0) {
         curl_mprintf("RTP PAYLOAD CORRUPTED [%s]\n", data + i);
-        /* return failure; */
+#if 0
+        return failure;
+#endif
       }
     }
     else {
       if(memcmp(RTP_DATA, data + i, message_size - i) != 0) {
         curl_mprintf("RTP PAYLOAD END CORRUPTED (%d), [%s]\n",
                      message_size - i, data + i);
-        /* return failure; */
+#if 0
+        return failure;
+#endif
       }
     }
   }

tests/server/dnsd.c

@@ -632,7 +632,9 @@ static int test_dnsd(int argc, char **argv)
       clear_advisor_read_lock(loglockfile);
     }
 
-    /* logmsg("end of one transfer"); */
+#if 0
+    logmsg("end of one transfer");
+#endif
   }
 
 dnsd_cleanup: