Use the appropriate string search functions instead of strstr everywhere.

This mostly means using strchr, but I also found:
  option_parser.c:load_ini_file:
    - replace multiple calls to strstr with strpbrk
  notification.c:notification_init:
    - replace string_replace in a while loop with a single call to
      string_replace_char

redo string replace all

dunstify.c

@@ -199,7 +199,7 @@ void closed(NotifyNotification *n, gpointer foo)
 void add_action(NotifyNotification *n, char *str)
 {
     char *action = str;
-    char *label = strstr(str, ",");
+    char *label = strchr(str, ',');
 
     if (!label || *(label+1) == '\0') {
         g_printerr("Malformed action. Excpected \"action,label\", got \"%s\"", str);
@@ -215,14 +215,14 @@ void add_action(NotifyNotification *n, char *str)
 void add_hint(NotifyNotification *n, char *str)
 {
     char *type = str;
-    char *name = strstr(str, ":");
+    char *name = strchr(str, ':');
     if (!name || *(name+1) == '\0') {
         g_printerr("Malformed hint. Expected \"type:name:value\", got \"%s\"", str);
         return;
     }
     *name = '\0';
     name++;
-    char *value = strstr(name, ":");
+    char *value = strchr(name, ':');
     if (!value || *(value+1) == '\0') {
         g_printerr("Malformed hint. Expected \"type:name:value\", got \"%s\"", str);
         return;

src/option_parser.c

@@ -214,7 +214,7 @@ int load_ini_file(FILE * fp)
                         continue;
 
                 if (*start == '[') {
-                        char *end = strstr(start + 1, "]");
+                        char *end = strchr(start + 1, ']');
                         if (!end) {
                                 printf
                                     ("Warning: invalid config file at line %d\n",
@@ -232,7 +232,7 @@ int load_ini_file(FILE * fp)
                         continue;
                 }
 
-                char *equal = strstr(start + 1, "=");
+                char *equal = strchr(start + 1, '=');
                 if (!equal) {
                         printf("Warning: invalid config file at line %d\n",
                                line_num);
@@ -244,9 +244,9 @@ int load_ini_file(FILE * fp)
                 char *key = g_strstrip(start);
                 char *value = g_strstrip(equal + 1);
 
-                char *quote = strstr(value, "\"");
+                char *quote = strchr(value, '"');
                 if (quote) {
-                        char *closing_quote = strstr(quote + 1, "\"");
+                        char *closing_quote = strchr(quote + 1, '"');
                         if (!closing_quote) {
                                 printf
                                     ("Warning: invalid config file at line %d\n",
@@ -257,9 +257,7 @@ int load_ini_file(FILE * fp)
 
                         closing_quote = '\0';
                 } else {
-                        char *comment = strstr(value, "#");
+                        char *comment = strpbrk(value, "#;");
-                        if (!comment)
-                                comment = strstr(value, ";");
                         if (comment)
                                 comment = '\0';
                 }
@@ -291,7 +289,7 @@ int cmdline_find_option(char *key)
                 return -1;
         }
         char *key1 = g_strdup(key);
-        char *key2 = strstr(key1, "/");
+        char *key2 = strchr(key1, '/');
 
         if (key2) {
                 *key2 = '\0';

src/x.c

@@ -1383,7 +1383,7 @@ void x_shortcut_init(keyboard_shortcut * ks)
         if (str == NULL)
                 die("Unable to allocate memory", EXIT_FAILURE);
 
-        while (strstr(str, "+")) {
+        while (strchr(str, '+')) {
                 char *mod = str;
                 while (*str != '+')
                         str++;